The use of British weaponry by Saudi Arabia and its allies in the conflict in Yemen is to be investigated by a Parliamentary committee following growing complaints that the UK's burgeoning arms exports to countries involved in the war are escaping scrutiny.

Nearly £3bn of British-made military equipment, including £1bn of bombs, rockets and missiles, has been authorised for export to Saudi Arabia since the oil-rich kingdom and its allies began an intervention in Yemen a year ago which has seen multiple claims of human rights violations during air strikes against Iranian-backed rebels.

Saudi Arabia is Britain's biggest arms customer and it is widely claimed that UK-supplied weaponry, including Tornado and Typhoon jets as well as Paveway precision bombs, has been deployed in the campaign against Houthi forces. Some 2,800 civilians have been killed in the war, according to the United Nations.

Britain has come under increasing pressure from international bodies, including the UN Secretary General Ban Ki Moon and the European Parliament, to halt arms exports to Saudi Arabia because of the conflict. A separate committee of MPs found last month that there was "overwhelming" evidence of breaches of humanitarian law by the Saudi-led coalition in Yemen.

But despite calls from campaigners and MPs for the use of British weaponry in Yemen, in particular in connection with alleged breaches of the laws of war, to be investigated, the Parliamentary committee set up to monitor Britain's £12bn arms export industry had not met for nine months since the beginning of the air strikes. A protracted delay in appointing new chairman of the committee following the retirement of his predecessor was blamed.

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Critics warned that the hiatus has allowed the Government to dramatically increase arms sales to Saudi Arabia and other Middle Eastern countries without independent oversight. In the third quarter of 2015, export licences to Saudi Arabia worth £1bn alone were approved compared to £9m in the same period for the previous year. The deals reportedly included precision Paveway IV bombs manufactured in Britain which had been originally earmarked for delivery to the RAF but were instead diverted to Saudi Arabia as it urgently sought to replenish stocks.

On 10 March the Committees on Arms Export Controls (CAEC), which was finally re-formed last month and is made up of members of four other influential select committees, announced a wide-ranging investigation into the use of UK weaponry in Yemen, including whether the Government is adhering to its own criteria in granting arms export licences to Saudi Arabia and other countries involved in the conflict, including the United Arab Emirates, Bahrain and Qatar.

10 examples of Saudi Arabia's human rights abuses Show all 10 1 /10 10 examples of Saudi Arabia's human rights abuses 10 examples of Saudi Arabia's human rights abuses In October 2014, three lawyers, Dr Abdulrahman al-Subaihi, Bander al-Nogaithan and Abdulrahman al-Rumaih , were sentenced to up to eight years in prison for using Twitter to criticize the Ministry of Justice. AFP/Getty Images 10 examples of Saudi Arabia's human rights abuses In March 2015, Yemen’s Sunni President Abd-Rabbu Mansour Hadi was forced into exile after a Shia-led insurgency. A Saudi Arabia-led coalition has responded with air strikes in order to reinstate Mr Hadi. It has since been accused of committing war crimes in the country. Getty Images 10 examples of Saudi Arabia's human rights abuses Women who supported the Women2Drive campaign, launched in 2011 to challenge the ban on women driving vehicles, faced harassment and intimidation by the authorities. The government warned that women drivers would face arrest. Getty Images 10 examples of Saudi Arabia's human rights abuses Members of the Kingdom’s Shia minority, most of whom live in the oil-rich Eastern Province, continue to face discrimination that limits their access to government services and employment. Activists have received death sentences or long prison terms for their alleged participation in protests in 2011 and 2012. Getty Images 10 examples of Saudi Arabia's human rights abuses All public gatherings are prohibited under an order issued by the Interior Ministry in 2011. Those defy the ban face arrest, prosecution and imprisonment on charges such as “inciting people against the authorities”. Getty Images 10 examples of Saudi Arabia's human rights abuses In March 2014, the Interior Ministry stated that authorities had deported over 370,000 foreign migrants and that 18,000 others were in detention. Thousands of workers were returned to Somalia and other states where they were at risk of human rights abuses, with large numbers also returned to Yemen, in order to open more jobs to Saudi Arabians. Many migrants reported that prior to their deportation they had been packed into overcrowded makeshift detention facilities where they received little food and water and were abused by guards. Getty Images 10 examples of Saudi Arabia's human rights abuses The Saudi Arabian authorities continue to deny access to independent human rights organisations like Amnesty International, and they have been known to take punitive action, including through the courts, against activists and family members of victims who contact Amnesty. Getty Images 10 examples of Saudi Arabia's human rights abuses Raif Badawi was sentenced to 1000 lashes and 10 years in prison for using his liberal blog to criticise Saudi Arabia’s clerics. He has already received 50 lashes, which have reportedly left him in poor health. Carsten Koall/Getty Images 10 examples of Saudi Arabia's human rights abuses Dawood al-Marhoon was arrested aged 17 for participating in an anti-government protest. After refusing to spy on his fellow protestors, he was tortured and forced to sign a blank document that would later contain his ‘confession’. At Dawood’s trial, the prosecution requested death by crucifixion while refusing him a lawyer. Getty Images 10 examples of Saudi Arabia's human rights abuses Ali Mohammed al-Nimr was arrested in 2012 aged either 16 or 17 for participating in protests during the Arab spring. His sentence includes beheading and crucifixion. The international community has spoken out against the punishment and has called on Saudi Arabia to stop. He is the nephew of a prominent government dissident. Getty

Chris White, the new chairman of CAEC, said: "The defence and security industry is one of the UK's most important exporters; however, it is vital that its financial success does not come at a cost to the nation's strategic interests.

"We have launched this inquiry to understand what role UK-made arms are playing in the on-going conflict in Yemen. Have the criteria set by the Government for granting arms export licences in the region been respected and what should be the consequences if they have not?"

The inquiry is potentially difficult for the Government, which has been careful to maintain its defence relationship with the Saudis as the kingdom pursues a more muscular foreign policy with interventions not only in Yemen but also in Syria.

Saudi Arabian soldiers shelling positions in Yemen. (Getty Images)

Under its previous chairman, Sir John Stanley, CAEC had a strong record for holding to ministers to account and exposing flaws in the arms control system, including a decision by the Coalition to allow the export to Syria of substances that could have been used for the production of chemical weapons.

The Government insists that it operates one of the most transparent and stringent arms export licensing systems in the world. It emerged in January that British military advisers posted to Saudi Arabia have access to the command and control centre from the air strikes on Yemen are being co-ordinated and can see target lists, although they play no role in choosing them. The Saudi authorities have strongly denied any deliberate violations of humanitarian safeguards.

But campaigners have warned of indiscriminate targeting of the civilian population in Yemen, including allegedly deliberate strikes on electricity and water plants. Last year, coalition strikes also hit a hospital and mobile clinic operated by Medecins Sans Frontieres as well as several schools. Amnesty International has criticised "a pattern of appalling disregard for civilian lives displayed by the Saudi Arabia-led military coalition".

Lawyers acting on behalf of the Campaign Against Arms Trade (CAAT) are also threatening legal proceedings against the Department for Business, Innovation and Skills, which is in charge of approving export licences, for allegedly failing in its duty to prevent violations of human rights protections.

Among the areas that will be looked at by CAEC is extending the role of the Department for International Development in granting licences to assess the impact of any weaponry sale on development in they buying country.