British soldiers who have served in Iraq may face prosecution for crimes including murder, the head of the unit established by the Ministry of Defence to investigate allegations of torture and unlawful killing in the war-torn country has said.

In his first major interview, Mark Warwick, a former police detective in charge of the Iraq Historic Allegations Team (Ihat), told The Independent that he believed there would be sufficient evidence to justify criminal charges.

“There are serious allegations that we are investigating across the whole range of Ihat investigations, which incorporates homicide, where I feel there is significant evidence to be obtained to put a strong case before the Service Prosecuting Authority to prosecute and charge,” he said.

Ihat’s caseload of allegations of ill-treatment or unlawful killing by British forces in Iraq between 2003 and 2009 has risen tenfold since it was established. In 2010, it was dealing with cases involving 152 victims. It is now dealing with more than 1,500 victims, according to Ihat’s latest quarterly update. Of these, 280 are victims of alleged unlawful killing by British forces in Iraq, but more than 200 of these cases have yet to be investigated, with just 25 under investigation.

Of 1,235 alleged cases of ill-treatment, including accusations of rape and torture, only 45 are under investigation.

Ihat’s initial target for completion of its investigations was 2016 but this will not be met. And, although the unit is funded until 2019, its work may not be finished by then.

Where are they now? The faces of the Iraq war five years on Show all 31 1 /31 Where are they now? The faces of the Iraq war five years on Where are they now? The faces of the Iraq war five years on Five years since the most divisive war of modern times began, many of the prime movers have faded from the headlines. GETTY IMAGES Where are they now? The faces of the Iraq war five years on KOFI ANNAN: The UN secretary-general at the time knew he had to keep his mouth shut on the Iraq crisis as the big powers on the UN Security Council slugged it out. But he finally spoke his mind in a BBC interview a few months after the invasion, saying that the war had been "illegal" because it was not authorised by the Security Council, and voicing his regret that a second UN resolution had not been achieved in the final days before the war began. Since leaving the UN in December 2006, he has been based in Geneva, where he has set up a foundation, the Global Humanitarian Forum, of which he is president. Acting in an individual capacity, the Ghanaian career diplomat was called in as chief mediator to broker a power-sharing agreement between rival factions in Kenya after the disputed elections of December 2007. GETTY IMAGES Where are they now? The faces of the Iraq war five years on MOHAMMED SAEED AL-SAHHAF: Those leading Saddam's regime had their work cut out during the US-led invasion. But few had it tougher than information minister Mohammed Saeed al-Sahhaf, handed the job of putting a positive spin on Iraq's war effort and earning the nickname Comical Ali for his efforts. As tracer-fire lit the skies and coalition troops marched ever nearer to Baghdad, al-Sahhaf would tell the world that Iraqi forces had the "American donkeys" on the run. He gained a cult following, and his face appeared on T-shirts and mugs. One fan was George Bush, who said he interrupted meetings to tune in to Comical Ali's broadcasts. Perhaps the favour of the President explains why he was released soon after giving himself up to US forces in June 2003. He is now living a more low-profile life in the United Arab Emirates. GETTY IMAGES Where are they now? The faces of the Iraq war five years on HANS BLIX: The quietly spoken Swede was the chief UN weapons inspector in the run-up to invasion. Blix had given Saddam a clean bill of health on nuclear arms while head of the UN's nuclear agency. The White House neocons suspected that his neutrality translated as pro-Iraq bias and ordered a CIA probe into his background. His reports to the Security Council became the focus of global interest as the administration stepped up demands for a "smoking gun" that would justify invasion and Blix was under heavy pressure to endorse Washington's belief that "weapons of mass destruction" had been stockpiled by Iraq. His inspections were cut short in the rush to war. Blix left the UN in 2003, and founded and chairs the Stockholm-based Weapons of Mass Destruction Commission, an independent think-tank funded by Sweden. GETTY IMAGES Where are they now? The faces of the Iraq war five years on AYATOLLAH ALI AL-SISTANI: As the supreme leader of the Shia majority in Iraq, the war catapulted the enigmatic and elderly Ayatollah Ali al-Sistani into the position of potentially the country's most important figure. His reputation as a moderate meant he was courted by the US. And despite his refusal to meet US officials directly, he has cooperated with coalition forces and the new Iraqi government. Little on Iraq's future could be agreed without the say-so of al-Sistani, who had a hand in the formulation of the election process and drafting of the Iraqi constitution. Shia ministers seek his advice. Yet, with his public appearances growing rarer, concerns have arisen over his health and the dangerous power vacuum that could emerge at his death. He now spends his days in an apartment in Najaf, the spiritual centre for Iraq's Shia Muslims. GETTY IMAGES Where are they now? The faces of the Iraq war five years on LORD HUTTON: Lord Hutton chaired the inquiry into the death of Dr David Kelly, who committed suicide shortly after he was exposed as the source of a BBC story accusing the Government of "sexing-up" its intelligence dossier making the case for war. The media praised the choice of Lord Hutton, who had a reputation for being independent minded, to head the inquiry. But his report, in January 2004 delivered a severe blow to the BBC, allowing Tony Blair and his spin doctor, Alastair Campbell, to claim vindication. Greg Dyke, the BBC's director general, resigned. Andrew Gilligan, the Today programme reporter responsible for the original story, lost his job. But Lord Hutton's criticism of the BBC was regarded by many as unduly harsh and led to the comment that he had given the "benefit of judgement to virtually everyone in the Government and no one in the BBC". Lord Hutton has since retired. But in 2006 he defended his report from the accusation – made most boldly by a front-page of The Independent – that it was a whitewash. He said media criticism had failed to take into account his terms of reference, which prevented any investigation of the reliability of the intelligence supplied to the Government AFP/GETTY IMAGES Where are they now? The faces of the Iraq war five years on ROBIN COOK: The former foreign secretary's resignation from the Cabinet on the eve of the key Commons vote that authorised the invasion made him a hero of the UK anti-war movement. Cook electrified the highly charged debate on the war with his resignation speech. MPs broke with tradition to applaud the 12-minute address after he predicted: "Iraq probably has no weapons of mass destruction in the commonly understood sense of the term – namely a credible device capable of being delivered against a strategic city target." He remained loyal on all issues apart from Iraq and, ironically, played an important role bolstering support for Labour colleagues who had backed the party line on the invasion during the 2005 election. Cook collapsed and died suddenly while walking in the Scottish hills in August that year. GETTY IMAGES Where are they now? The faces of the Iraq war five years on PAUL WOLFOWITZ: Paul Wolfowitz was a prime intellectual architect of a war he had advocated since the early 1990s. He has been a lifelong supporter of Israel, and a believer in "pre-emptive" war. Like many neocons, he saw democratic government in Baghdad, spreading across the Arab world, as the best guarantee of Israel's security. Alas, management and good judgement were not his strong suits. As deputy to Rumsfeld, he shared his boss's belief that a small force would be sufficient, and argued that reconstruction would be paid for by Iraq's oil revenues. Wolfowitz left the administration in 2005 to become President of the World Bank. His tenure ended in disgrace in June 2007, amid charges he had used his position to arrange a promotion for his girlfriend. He is now a scholar at the neocon think-tank the American Enterprise Institute GETTY IMAGES Where are they now? The faces of the Iraq war five years on GENERAL SIR MIKE JACKSON: Jackson became known to the wider public when he led Nato troops into Kosovo. He also refused to follow the order of General Wesley Clark, his superior as supreme commander of Nato, to confront Russian forces at Pristina airport, saying he had no intention of starting a third world war. General Jackson's reputation suffered from the Iraq debacle. After retiring as head of the Army he criticised the Americans for having no post-invasion plan and the MoD for failing to understand the ethos of the armed forces. The approach of the US neocons he described as intellectually bankrupt. Jackson's critics said troops who suffered equipment shortages and those who had abused civilians were serving in his army, so he ought to bear some responsibility for what happened GETTY IMAGES Where are they now? The faces of the Iraq war five years on DONALD RUMSFELD: Together with his old friend and one-time protégé Dick Cheney, Rumsfeld led the hawks who won the battle for Bush's heart. As Defence Secretary, he was advocating an attack on Iraq shortly after 9/11, warning of the WMD menace posed by Saddam. He saw the invasion as a test of his belief that small, hi-tech forces could win modern wars. They could – but were insufficient to keep the peace. Having wrested control of the occupation from the State Department, Rumsfeld bears responsibility for the pre- "surge" fiasco, including the shame of Abu Ghraib. Arrogant and bullying, more nationalist than neocon, he will go down as perhaps the most controversial Pentagon chief ever. Twice he was target of a "generals' revolt"; in summer 2001 and early 2006. He was forced out in November 2006, after the Democrats recaptured Congress. GETTY IMAGES Where are they now? The faces of the Iraq war five years on ANDREW GILLIGAN: Most people were asleep when the defence correspondent of BBC Radio 4 Today uttered the words that made him famous. Two months after the invasion, in a 6.07am report, Gilligan alleged the Government had knowingly misled the country on the case for war. The ensuing row led to an inquiry by Lord Hutton that threatened to destroy the BBC, damned Gilligan's journalistic rigour and cost him his job. It was, in some respects, the making of him. Profile transformed, he was invited to lecture the Edinburgh Television Festival and hired to present documentaries for Channel 4's Dispatches. Employed by the London Evening Standard as a columnist and investigative reporter, he has led the paper's fight with London Mayor Ken Livingstone. Gilligan, 39, is shortlisted as Reporter of the Year at next month's British Press Awards GETTY IMAGES Where are they now? The faces of the Iraq war five years on COLIN POWELL: The collateral damage of the Iraq war included Powell's reputation. Secretary of State during Bush's first term, he was expected to be a voice of wisdom and moderation, but he was outmanoeuvred by the Rumsfeld/Cheney alliance. Humiliation was heaped on humiliation in the months before the war. Bush ignored Powell's pre-war "Pottery Barn" warning about Iraq – "You break it, you own it", and then told Saudi Ambassador Prince Bandar before his own Secretary of State that he'd decided to invade. Worst of all was Powell's February 2003 presentation at the UN; his every major claim on WMD was proved wrong. As Powell has admitted, he will have to live with that for ever. He must also live with a question: why, given his reservations about the war, did he not resign? Since leaving government he has, like so many old soldiers, just faded away. GETTY IMAGES Where are they now? The faces of the Iraq war five years on CONDOLEEZZA RICE: Bush's National Security Adviser in the run-up to the invasion was, by common consent, not up to the job, steamrollered or ignored by the "big beasts" – Powell, Rumsfeld and Cheney. After the 2004 election, she replaced Powell as Secretary of State. She made a promising start, seeking to repair relations with US allies fractured by the war. But despite close ties with the President that Powell never enjoyed, she has been a disappointment. Her reputation never recovered after she described Israel's invasion of Lebanon in 2006 as "the birth pangs of the new Middle East". Her efforts to broker an Israeli/Palestinian deal by the end of this year seem futile. Once mentioned as a Vice-Presidential, even Presidential, candidate in 2008, Rice is likely to return to a top post at Stanford University, California, when Bush leaves office. GETTY IMAGES Where are they now? The faces of the Iraq war five years on ALI ABBAS: In a war that delivered many images of devastation and despair, one hit a nerve more than any other – that of a 12-year-old boy, who had lost both arms and suffered severe burns over 60 per cent of his body when a US missile struck his home, killing his entire family and many of his relatives. The front page pictures of Ali Abbas, soon renamed "Tragic Ali" by the press, served as a potent reminder of the heavy price paid for the fall of Saddam. He was airlifted to Kuwait for immediate treatment at the request of Iraqi medics, who feared he may not survive his injuries. After receiving extensive skin grafts, he was flown to London in the Kuwaiti prime minister's private plane for further treatment. Ali not only survived, but has managed to rebuild a life for himself in Britain, and has been trained to use artificial limbs. AFP/GETTY IMAGES Where are they now? The faces of the Iraq war five years on ALASTAIR CAMPBELL: The days before the invasion of Iraq sealed Campbell's reputation as the maestro of spin. The former Daily Mirror political editor was at the heart of efforts to make the case for war against Saddam. He vehemently denied allegations broadcast by the BBC that the Government "sexed up" claims about weapons of mass destruction. The furore surrounding Campbell's battle with the BBC over Andrew Gilligan's report ended in tragedy, with the death of government weapons expert, Dr David Kelly, Gilligan's primary source for the story. The Hutton Inquiry that followed gave an unprecedented glimpse into the innermost workings of Government and put the spotlight on Campbell as never before. He stood down as Tony Blair's director of communications during the hearings. Campbell has since published the first volume of his diaries, toured the country with a one-man show and raised thousands of pounds for Leukaemia Research. GETTY IMAGES Where are they now? The faces of the Iraq war five years on DICK CHENEY: "Dick Cheney I don't know any more," said Brent Scowcroft, his colleague, on the transformation of a cautious, moderate Defense Secretary in the first Gulf war into the leader of the hawks against Saddam second time round. As perhaps the most influential US Vice-President ever, Cheney was scaremonger-in-chief before the war, warning that Saddam had "reconstituted his nuclear weapons". Like Donald Rumsfeld, he's not so much a neocon as a "Hobbesian nationalist", believing the US must do what it takes to protect itself – thus his disdain for the UN, support for torture and belief in a powerful presidency. Despite the loss of his chief of staff, Lewis Libby (convicted of perjury in 2007), and huge unpopularity, Cheney is still powerful. He is a leading advocate of military strikes against Iran GETTY IMAGES Where are they now? The faces of the Iraq war five years on TARIQ AZIZ: After Saddam himself, the best-known Iraqi leader in the West. The cigar-puffing, bespectacled figure of Tariq Aziz was Iraq's foreign minister at the time of the first Gulf War. He was used by Saddam as a moderate front, regularly appearing on western television screens speaking excellent English. By the time of the 2003 invasion, he had risen to the heights of deputy prime minister, despite being the only Christian in the Sunni-dominated Baathist regime. His cigar case may have turned up in the possession of Boris Johnson recently, but Aziz himself hasn't seen the light of day since he was captured by US troops in April 2003, save for a brief appearance as a defence witness at Saddam's trial. He has been languishing in prison ever since and has yet to face a trial of his own. His health has deteriorated, while an Iraqi Christian leader has demanded his release. GETTY IMAGES Where are they now? The faces of the Iraq war five years on LYNNDIE ENGLAND and CHARLES GRANER: England, a guard, and her fellow guard and lover, Graner, appeared in shocking photographs of abuse of inmates at the Abu Ghraib prison in Baghdad. Both were among those subsequently charged over the affair and faced courts martial. Graner was jailed for 10 years and England for three. Both claimed that they were encouraged to carry out the abuse by senior officers. England gave birth to Charles Graner's son, christened Carter Allan England, in October 2004. She was paroled in March 2007 after serving 521 days and will receive a dishonourable discharge in September. She has claimed, in various interviews, that she was forced into her actions by Graner. Graner himself married another fellow Abu Ghraib guard, Megan Ambuhl, who had herself pleaded guilty to abuse charges, in 2005. GETTY IMAGES Where are they now? The faces of the Iraq war five years on GEORGE W BUSH: The man ultimately responsible for what may prove America's greatest ever foreign policy blunder. Almost certainly, Bush made up his mind to attack Iraq by mid-2002 at the latest. The reasons are still not clear. Was it Saddam's imagined weapons of mass destruction? Oil? The neocon conceit that democracy could be imposed by force? Or a desire to prove his father wrong for not toppling Saddam in 1991? Probably a mixture of all the above. Bush's high point was the "mission accomplished" moment on a US carrier in May 2003. His popularity has since ebbed to near-record lows. His 2007 troop surge has worked up to a point, but a lasting solution in Iraq is far off. Stubborn, incurious, Bush cannot admit that the biggest beneficiary of the mess is his arch foe Iran. He will surely go down as one of the worst US presidents ever, if not the worst. GETTY IMAGES Where are they now? The faces of the Iraq war five years on AHMED CHALABI: Few Iraqi politicians have displayed the knack of making enemies with the regularity of Ahmed Chalabi. As an exile lobbying for the overthrow of Saddam, his Iraqi National Congress was blamed by many for inciting war by providing US security forces with false information about Saddam's "weapons of mass destruction" and links with al-Qa'ida. And though he was championed by the US before the invasion of Iraq, his criticisms of the occupation soon saw him sidelined. After a brief stint as deputy prime minister, he failed to win a seat in the Iraqi parliamentary elections. He is also wanted in Jordan over embezzlement charges. But Chalabi is making a remarkable political comeback – his connections across the religious and political divides in Iraq have become an invaluable commodity. The government has handed him the considerable task of restoring essential services to Baghdad. He currently lives in a heavily protected compound in the al-Mansur district of the capital. GETTY IMAGES Where are they now? The faces of the Iraq war five years on COL TIM COLLINS: Tim Collins achieved fame for a stirring speech to his troops as they prepared for battle. After the invasion, however, he was accused by an American officer of abusing Iraqi civilians and prisoners of war. He was cleared by the Royal Military Police and subsequently sued the Sunday Express and Sunday Mirror for damages, which were said to be substantial. In October 2003, Col Collins was awarded an OBE, but he resigned from the military three months later. He has commented widely in the media and has become critical of the Iraq war and Western foreign policy in general, saying: "The UK and US pour blood and treasure into overseas campaigns which seem to have no ending and no goal... Clearly I was naive." His memoir, Rules of Engagement, was generally well received. GETTY IMAGES Where are they now? The faces of the Iraq war five years on DOMINIQUE DE VILLEPIN: Dominique de Villepin, then Prime Minister of France, was the mouthpiece for French anti-war opinion. On 14 February 2003, he addressed the UN in opposition to a second resolution on Iraq, earning loud applause. In the run-up to the 2007 French presidential election, de Villepin was touted as a rival to Nicolas Sarkozy for the candidacy of the centre-right UMP party. Sarkozy was implicated in a corruption scandal over arms sales to Taiwan. When the charges proved insubstantial, it was revealed that de Villepin had been aware of their falsity, but had allegedly used the affair to taint his rival. Sarkozy ran unopposed for the UMP candidacy, was reluctantly endorsed by de Villepin, and ended up in the Elysée Palace. De Villepin has earned back some respect from the French public with his criticism of Sarkozy's unpopular regime. GETTY IMAGES Where are they now? The faces of the Iraq war five years on JESSICA LYNCH: The capture and rescue of Jessica Lynch, a US Army private, received huge media attention. The US authorities claimed that she had bravely fought back after being ambushed by Iraqi forces, and then suffered abuse and rape in captivity. Most of these allegations turned out to be untrue, and her "rescue" was stage-managed with US forces firing blanks while they "stormed" a hospital which had, in fact, been abandoned by the Iraqi military. Lynch herself exposed much of the news manipulation after returning to the US, saying that she could not "fight back" because her rifle had jammed, as had those of some of her comrades. She stressed that her treatment by Iraqi medical staff had been excellent and denied that she'd been sexually assaulted. Lynch gave evidence last year before a US Congressional Committee on the topic of official news manipulation and met the family of Pat Tillman, a gridiron football hero who joined up after September 11 and was killed in Afghanistan. The Pentagon claimed at first that he died in action but was later forced to admit that he died from "friendly fire". Lynch joined West Virginia University on a military scholarship, but sought to keep her military past away from public knowledge. In January 2007 she gave birth to a daughter, Dakota Ann, named after her friend and fellow soldier, Lori Ann Piestewa, the first coalition servicewoman to be killed in the Iraq war GETTY IMAGES Where are they now? The faces of the Iraq war five years on RAGEH OMAAR: The face of the BBC during the bombing of Baghdad, baby-faced Omaar, 40, became internationally famous and was dubbed the "Scud Stud" by the red-tops. But he was never the adrenalin-junkie war correspondent that some imagined and, as a devoted family man, resisted any attempts by the BBC to style him as such. Critical of Western media organisations' coverage of the aftermath of the war, the Somali-born journalist broke from the corporation because he "wanted to be free". He wrote a book called Only Half of Me on the experiences of British Muslims and then, in 2006, joined the news channel Al Jazeera English, where he presents and sometimes produces documentaries from around the world, most notably reporting last year from the siege of the Red Mosque in Islamabad. He has just revisited the country that made his name for a documentary, Back to Iraq, to be shown on Saturday on Al Jazeera English. GETTY IMAGES Where are they now? The faces of the Iraq war five years on JACQUES CHIRAC: Chirac's re-election to the French presidency in 2002 was controversial: voters had only been given a choice between him and his far-right rival, Jean-Marie Le Pen. But Chirac's popularity was boosted by his opposition to military action in Iraq, and he became the anti-war movement's leading international figure. This raised hackles in the US and UK. When Chirac threatened to veto a second UN Iraq resolution in March 2003 – saying weapons inspectors should do their jobs – London and Washington said France would never allow a second resolution, thus blocking the UN route. Chirac's presidency was plagued by allegations of corruption. He stepped down last year and has been threatened with criminal charges over embezzlement of public funds during his time as mayor of Paris GETTY IMAGES Where are they now? The faces of the Iraq war five years on JONATHAN POWELL: As Tony Blair's chief of staff, the tousle-haired Jonathan Powell was at the PM's side during at every key moment in the build-up to war. Along with Alastair Campbell, he was Blair's most trusted confidant as the No 10 struggled to win support for the action. Powell, a former diplomat, was heavily involved in the drafting of the intelligence dossier that made the case for the invasion and the Hutton Inquiry heard how he urged MI6 chief John Scarlett to toughen the dossier's language. He was not criticised by Lord Hutton or the subsequent Butler inquiry, although the latter had strong words about the informal "sofa style" of government that had developed under Powell. He left Downing Street in June 2007 when Blair stepped down. He later took up a position at Morgan Stanley's investment banking arm. GETTY IMAGES Where are they now? The faces of the Iraq war five years on GENERAL TOMMY FRANKS: Franks's career was at its apex after Afghanistan in 2001, which at the time was a small victorious war with the Taliban, won with minimal American and British casualties. But then came Iraq, the graveyard of so many reputations, and the US military commander was charged with a series of misjudgements as George W Bush's official declaration of victory began its unravelling. Franks was accused of focusing overwhelmingly on the removal of Saddam and failing to foresee the insurgency. He also failed, say critics, to make reconciliation and reconstruction the prime objective after Saddam's fall. Further accusations included his failure to settle the internecine dispute between two deputies, Lieutenant General Michael "Rifle" De Long and Lieutenant General John "Mad Arab" Abizaid, later the US commander in Iraq. After his retirement, General Franks published his memoirs, American Soldier, to good sales. He also opened Franks & Associates, a consultancy specialising in disaster recovery, and in December 2005 was appointed a director of the Bank of America. Franks endorsed George Bush for re-election in 2004. He faced severe criticism when it was revealed that he had charged $100,000 to have his name linked with the Coalition to Salute American Heroes, a fund to raise money for wounded US servicemen. He has severed links with the organisation. GETTY IMAGES Where are they now? The faces of the Iraq war five years on IAIN DUNCAN SMITH: Journalists were still being briefed a week before the invasion that military action could be avoided. To the dismay of the Government, Iain Duncan Smith, the Tory leader, emerged from a meeting with the Prime Minister on 13 March 2003 to tell the nation that war looked almost certain. Duncan Smith argued strongly in favour of the invasion and his party's support guaranteed Blair a Commons majority for the war. By the next election, he had resigned the leadership, but his stance in 2003 made it difficult for the Tories to attack Labour over the war and its aftermath. Duncan Smith still supports the action, but says Blair should have concentrated on the need to topple Saddam rather than the dangers of Iraq's non-existent weapons of mass destruction. Now a Tory backbencher, he concentrates on inner-city deprivation. GETTY IMAGES Where are they now? The faces of the Iraq war five years on CLARE SHORT: The biggest surprise about Clare Short's resignation as International Development Secretary was that it took so long. Eleven days before the invasion, she described Blair as "reckless" and said she would quit the Cabinet if Britain went to war without a clear UN mandate. But she was still at the top table when the troops went in – a decision that cost her much respect on the Labour left. Short did not step down until 12 May, accusing the Prime Minister of breaking promises over the role of the UN in reconstructing Iraq. She became a vehement critic of New Labour, describing it as arrogant and unprincipled and claiming Blair had made the world a more dangerous place. She will not stand at the next general election and sits as an "Independent Labour" MP. Nigel Morris GETTY IMAGES Where are they now? The faces of the Iraq war five years on LORD GOLDSMITH: The Attorney General's advice to the Government over the legality of the invasion was one of the most tendentious aspects of the war. The original advice, dated 7 March 2003 and seen only by Tony Blair and close advisers, was much more equivocal than the version presented to the Cabinet and military leaders 10 days later, authorising military intervention. In the first, Lord Goldsmith conceded that "a court might well conclude" that a second UN resolution expressly authorising force may be necessary. His critics claim the disparity is evidence that Goldsmith was leant on by the Government. Goldsmith claims there was no outside influence. Goldsmith left the Government last year. In January, he said he was going to work for an American law firm in London. Last week, his report into citizenship recommended that school-leavers swear an oath of allegiance to the Queen. GETTY IMAGES Where are they now? The faces of the Iraq war five years on TONY BLAIR: Tony Blair is Labour's most electorally successful leader and brought about a long-term shift in British politics. But the decision to invade Iraq will dominate his place in the history books. On 18 March 2003, Blair delivered a typically brilliant speech to the Commons to make the case for invading Iraq. He told MPs it was "palpably absurd" to believe Saddam Hussein had destroyed unaccounted-for anthrax, chemical munitions, sarin, botulinum toxin and a VX nerve agent programme. Blair staked his reputation on the war, despite being branded "Bliar" by anti-war campaigners. He has always defended the decision to invade and insisted it was right to remove Saddam. But the military campaign and its aftermath dominated his second term and hastened his political demise after his third election victory. Blair stood down last June and is now an official peace envoy to the Middle East. He has accepted posts with JP Morgan and the insurance company Zurich. GETTY IMAGES

“Over the next 12 to 18 months, we will review all the caseload to better understand the picture and then I think we can say whether 2019 seems realistic,” said Mr Warwick.

One of Ihat’s most notorious cases is that of Baha Mousa, an Iraqi hotel receptionist who died after being beaten, abused and restrained while held in custody by British soldiers in 2003. More than a decade on, Mr Warwick stressed that this remains “a live criminal investigation”.

Asked whether some cases could constitute war crimes, he said: “There are lots of significant cases that we are investigating and at the appropriate time it will be a matter for us to discuss with the SPA whether they meet the war-crimes threshold, but there are certainly serious allegations currently being investigated.”

A British soldier in Basra, Iraq in 2003. The conflict still casts a shadow over Westminster (Getty)

Five years after Ihat was established, there has yet to be a single prosecution. Human rights groups are losing patience with the lack of obvious progress.

“The incredibly slow pace at which Ihat is investigating allegations of criminality committed by UK soldiers against Iraqi civilians is wholly unacceptable,” said Carla Ferstman, the director of the human rights charity Redress. “Things seem to still be moving at a snail’s pace. We call upon the Government to ensure Ihat can, and does, do what it was set up to do, and to do it now. This cannot be a whitewash.”

But Mr Warwick appealed for patience with his team’s process. “I think people need to understand the complexity, the volume and the geography aspects of this, and you can’t underestimate putting those three factors together and trying to conduct ethical investigations,” he said.

Not every allegation will result in an investigation, with “proportionality” of the offence being taken into account: “What’s the likely outcome to be if we do a full investigation, and what’s the likely penalty if we convict someone?” he said.

“We would look at the credibility of the allegation in the first instance; and, when we’ve looked at a lot of these extra cases coming to us, some of them are duplicates of cases, some of them we’ve already identified as part of our own investigation process, and some are multiple allegations, where we would investigate as a single allegation,” he added.

Meanwhile, Britain remains under the scrutiny of the International Criminal Court (ICC), which is conducting a preliminary examination of allegations of war crimes by British forces in Iraq.