The BBC has revealed that G4S, the world's biggest security company, received warnings, from an anonymous person to its London Headquarters, concerning the suitability to employ Danny Fitzsimons seen here who was working for the Armor Group division in Iraq. Fitzsimons shot and killed Paul McGuigan and Darren Hoare, in what he claimed was a drunken brawl, just 36 hours after arriving in Iraq in 2009.

The G4S worker sent a series of emails to the company in London, warning them about Fitzsimons's previous convictions for firearms offences, violence and unstable behaviour relating to post-traumatic stress disorder.

The worker warned G4S: "I am alarmed that he will shortly be allowed to handle a weapon and be exposed to members of the public. "I am speaking out because I feel that people should not be put at risk. "The anonymous whistle blower signed one email "a concerned member of the public and father."

In response to these claims A G4S spokesman admitted that its screening of Danny Fitzsimons "was not completed in line with the company's procedures." They then added its vetting had been tightened since the incident.

Fitzsimons received a 20 year jail sentence for the murders instead of the death sentence, and his supporters claim he didn't receive the correct care and treatment from the MOD on his release. The BBC documentary titled Britain's Private War, screens tonight at 9 o clock and reveals the growing extent to which the UK government relies on armed security companies to protect its interests overseas.

Written and presented by Ann Salter