A man who was being hunted for the murder of a policewoman is understood to have escaped from Britain by disguising himself as a veiled Muslim woman.

Mustaf Jama, a prime suspect in the fatal shooting of PC Sharon Beshenivsky, assumed his sister’s identity — wearing the niqab and using her passport — to evade supposedly stringent checks at Heathrow, according to police sources.

The use of the niqab, which leaves only a narrow slit for the eyes, highlights flaws in British airport security. At the time, Jama was Britain’s most wanted man, while Heathrow was on a heightened state of alert after the 7/7 terrorist atrocities in London five months previously.

The Times has learnt that British immigration officers rarely carry out a visual check to match a passport photograph with a departing female passenger’s veiled face.

Details of Jama’s disguise emerged yesterday as his younger brother, Yusuf, awaited a life sentence for the murder of the police officer, who died during an armed robbery at a Bradford travel agency in November last year.

Detectives believe that Jama, 26, was allowed to board an international flight from Heathrow because no attempt was made to uncover his face. While British baggage security is among the strictest in the world, the system of identity checks is considered less rigorous than in countries such as France.

At the time of his escape, between Christmas Day last year and New Year’s Day, the 26-year-old Somali national, who had 21 criminal convictions, was the most wanted man in Britain. His photograph had been circulated to every police force, port and airport in the country after the bungled robbery in which PC Beshenivsky died and her colleague, PC Teresa Milburn, was seriously wounded.

David Davis, the Shadow Home Secretary, called for an urgent inquiry into the security breach. “The idea that in any circumstan-ces you could be let through passport control wearing a veil is barely credible,” he said. “Doing so when an all-persons bulletin for murder has been issued demonstrates that our borders are not just porous — they are non-existent.”

A Home Office spokesman confirmed yesterday that although immigration control staff had the power to ask people to remove the veil to prove their identity, it is not an automatic policy. The only visual checks at an airport that should always be made in relation to departing pasengers are at check-in and at the boarding gate. In each case, the task is the responsibility of the relevant airline. A BAA Heathrow spokesman said yesterday:

“Immigration control staff always do a visual check on people coming into the country but only random checks are made with outgoing passengers.”

The Times understands that police investigating the Beshenivsky murder received speci-fic intelligence about Jama’s veiled escape from what is regarded as a very reliable source. Jama — who made £600 from the robbery — is thought to be under armed protection in a semi-lawless region of Somalia where his family wields considerable influence.

The Times can also reveal that Jama’s father, who was once a Somali MP, is a cousin of Mohamed Siad Barre, the country’s former President who seized power in a 1969 military coup and led a brutal dictatorship until he was toppled in 1991. The wanted man’s uncle is the country’s former Foreign Minister.

Approaches have been made by Britain to the transitional Government in Somalia, which has offered its co-operation in any attempt to detain and extradite Jama but is understood to have minimal influence in the region where he is hiding.

The news adds to the controversy over the wearing of the veil in Britain. The debate was sparked in October when Jack Straw revealed that he asked Muslim women to remove the niqab before meetings in his Blackburn constituency. Tony Blair later described the veil as “a mark of separation”.

In October The Times revealed that a male suspect in a major anti-terrorist investigation evaded capture in Britain for several days by dressing in a burka. He was eventually arrested and is awaiting trial.

The full-face veil has regularly been used as a disguise in Iraq and Afghanistan by Islamist fighters, including several suicide bombers and at least one senior al-Qaeda leader.