Met chief: Bernard Hogan-Howe was rewarded with a peerage

Quite simply, it has rewritten the rule book for shambolic police investigations. Diabolical would be a more appropriate word to describe Operation Midland – the £2.5million inquiry into an alleged murderous, VIP paedophile ring involving a former prime minister, ex home secretary, one-time armed forces chief and heads of the security services.

Haunted by police failings in the Jimmy Savile case, obsessed with the idea that any abuse allegations should automatically be believed and under ferocious pressure from the likes of Labour deputy leader Tom Watson, officers abandoned common sense.

But as the rudderless investigation descended into a black comedy, it appeared detectives were auditioning for a 21st century revival of the Keystone Cops.

Imagine the scenes at the North Yorkshire home of former home secretary Leon Brittan where, just six weeks after his death, a line of officers did a fingertip search of his garden looking for signs of ‘disturbed earth’.

Detectives searching this property and his London house later took away dozens of items for further investigation – including a Teletubbies video.

In an excruciating 100-minute police interview, D-Day veteran Lord Bramall was asked if he could swim, if he ordered his accuser to eat his vomit, whether he chose to molest him on Remembrance Days and if disgraced TV presenter Savile was an accomplice.

Beech (pictured during a police interview) was today convicted of perverting the course of justice as well as fraud

If that wasn’t bad enough, police calmly carried out a follow-up interview shortly after his wife of 66 years had died. Within days of receiving Beech’s allegations, it should have been clear they were the work of an attention-seeking fantasist.

But detectives on Operation Midland took 370 witness statements, launched 1,700 ‘actions’ and produced 1,860 documents. The inquiry involved a minimum of 20 police officers full time.

In November 2012, Beech contacted Metropolitan Police officers on Operation Yewtree, the force’s umbrella investigation into spiralling claims against Savile and other celebrities.

His complaint was referred to Wiltshire Police and Beech was interviewed the following month, when he gave more details of supposed abuse by Savile, his late stepfather and others.

The fall-out over Beech's lies about a VIP paedophile ring has led to calls for deputy Labour leader Tom Watson (pictured) to quit after he publicly backed the accuser

He made no mention of VIPs, recollections were sketchy, and he struggled to answer basic questions. In May 2013, the Wiltshire probe was shelved due to insufficient evidence. A file saying so was returned to the Met.

After being snubbed by detectives, Beech began blogging on the internet about his alleged child sex abuse. In August 2014 he appeared in silhouette and with a disguised voice in an obscure satellite TV documentary under a different name claiming he was abused by Savile.

By the time the programme was broadcast, Beech was also in contact with Mark Conrad, a reporter from a hitherto unknown investigations website, Exaro.

Beech now named Tory ex-MP Harvey Proctor as being among his tormentors. His growing allegations caught the eye of a detective from Scotland Yard’s Operation Fairbank inquiry into alleged historic child sex abuse by politicians and other public figures.

By now Beech was using the pseudonym ‘Nick’ and had a bombshell tale to tell: he said he had witnessed the sadistic murder of three boys by various high-profile figures.

In October 2014, Beech provided Detective Sergeant James Townly with a list of 12 alleged abusers, including Lord Bramall, Sir Edward Heath, Lord Brittan, Mr Proctor, Labour peer Lord (Greville) Janner, ex-MI5 boss Sir Michael Hanley and ex-MI6 chief Sir Maurice Oldfield.

Police should not have taken such a list seriously – especially given Beech had made no mention of VIPs two years earlier. The decision not to check against Wiltshire Police files was a major blunder.

But they did take him seriously, almost certainly as a consequence of a new policy directive issued in November 2014, when Her Majesty’s Chief Inspector of Constabulary Sir Tom Winsor stated that ‘the presumption that a victim should always be believed should be institutionalised’.

Det Supt Kenny McDonald, who described Beech as ‘credible and true’, was cleared of wrongdoing

Deputy Assistant Commissioner Steve Rodhouse, perhaps smarting from overseeing a bungled previous inquiry into Savile, formally opened an investigation and briefed senior officers, including Yard chief Sir Bernard Hogan-Howe and Assistant Commissioner Patricia Gallan.

Within months of the probe commencing, a leading criminal psychologist was warning that Beech was very likely to be a fantasist.

The basic detective’s rule of ‘assume nothing, check everything’ was thrown out of the window in December 2014 when Detective Superintendent Kenny McDonald held a press conference at Scotland Yard to describe allegations made by ‘Nick’ as ‘credible and true’.

At that point officers hadn’t interviewed a single suspect, didn’t know who the alleged murder victims were, and hadn’t found a body. Sources claim Yard chiefs were so concerned about ‘undermining victim confidence’ in the police that they decided against asking Beech for permission to look at his computers and electronic devices.

Had they done so, they would established very quickly that he had carried out internet research to identify his victims and fabricate his story, and downloaded appalling child porn including images of children being raped.

It should not have taken long to establish that Heath and Mr Proctor were sworn enemies, yet Beech suggested that they were part of the same paedophile ring.

The suggestion that Sir Michael kidnapped Beech’s dog as a warning to comply with the abuse gang’s wishes was similarly outlandish.

Mr Proctor firmly believes that the fantasist effectively ended up running Operation Midland: calling the shots, putting pressure on police to make arrests and seeking updates on raids. Beech also demanded that officers should not speak to his ex-wife, a nurse who would have rubbished his story.

Deputy Assistant Commissioner Steve Rodhouse were cleared of misconduct in March 2017 despite calling Beech a credible witness

In February 2015 – despite lacking any firm corroboration – police took the decision to apply for search warrants to raid the homes of those accused by Beech.

No evidence was found and the Yard came under increasing pressure. The Daily Mail revealed in a front page article that the VIP child abuse inquiry was beginning to ‘unravel’ and that a number of officers now believed ‘Nick’ was a fantasist. Detectives had still not found ‘a shred of credible evidence’ and in March 2016 Operation Midland closed without a single arrest, let alone charge.

Eight months later, a report by a retired High Court judge savaged the Met for giving credence to Beech’s allegations – and ordered an inquiry into him for allegedly perverting the course of justice.

Sir Richard Henriques lambasted police over their searches of the accused men’s properties.

Officers had even handed a district judge inaccurate and misleading warrant applications, he said, adding that they had made a gross error in believing Beech.

But the worst was yet to come for the Met over Operation Midland.

Northumbria Police, which investigated Beech for perverting the course of justice and fraud, discovered evidence at his Gloucester home that he had downloaded hundreds of appalling child porn images and filmed an underage boy urinating in a toilet.

It is a macabre and barely believable post-script to an inquiry that continues to shame Scotland Yard.

Officers escape sanction

Not one police officer will face misconduct proceedings over the disastrous £2.5million inquiry into Carl Beech’s allegations.

Five officers were referred to the Independent Office for Police Conduct over fears they failed in their ‘duties and responsibilities’.

But last night it confirmed that no one on Operation Midland or those who supervised it would face any disciplinary action.

In any event, three detectives retired before the inquiry concluded – including senior investigating officer Detective Superintendent Diane Tudway.

Two further officers, Det Supt Kenny McDonald, who described Beech as ‘credible and true’, and Deputy Assistant Commissioner Steve Rodhouse were cleared of misconduct in March 2017.

This was despite a scathing 2016 report into Operation Midland by retired High Court judge Sir Richard Henriques who identified 43 separate blunders.

However he absolved then Metropolitan Police Commissioner Sir Bernard Hogan-Howe and his Assistant Commissioner Patricia Gallan, who had oversight of Operation Midland, of any blame.

Bizarrely, Mr McDonald’s now infamous ‘credible and true’ comments, which critics said prejudiced Operation Midland, were not even examined by watchdogs. He retired with an estimated £250,000 pension pot weeks before the Beech trial.

Mr Rodhouse is now a £175,000-a-year director general at the National Crime Agency.

Miss Gallan retired last year with an estimated £400,000 pension. Mrs Tudway was promoted to superintendent and retired on the eve of Beech’s trial.

Detective Sergeant James Townly, who conducted around 20 hours of interviews with Beech, now works in counter-terrorism. Sir Bernard was given a peerage.