The circumstances surrounding the murder of PC Sharon Beshenivsky would be disturbing at the best of times. She was shot by a gang whose members (foreign nationals) had extensive criminal records; they were considered for deportation but were allowed to stay in Britain because their homeland — Somalia — was determined to be too dangerous a place to which to send them back. If no other information about this killing had surfaced, questions would and should have been asked about the balance to be struck between law and order and deportation.

Yet, as we report today, matters are worse than they appear. One of those who was wanted for this murder — Mustaf Jama — is believed to have fled Britain in the days after the shooting, disguising himself as a veiled woman. His brother was one of five other men left to be tried and convicted of murder or manslaughter. Jama was able to sneak on to an international flight at Heathrow dressed in a niqab despite extensive publicity about this murder. His photograph had been circulated to every police force, port and airport in the country. Had he been asked to reveal his face he would have been detected in a moment. He is instead now believed to be at liberty in a region of Somalia where his family wields much influence — the very same Somalia that had been too dangerous for these criminals.

This shocking affair reveals fundamental lapses in what should surely be considered elementary security measures. Yet, in truth, this may not have been an isolated incident. While it is compulsory for those wearing the niqab to be examined (by a female immigration officer if that is what is preferred) when they enter this country, arrangements appear to be far less stringent if a woman (or in this dire incident, as it transpires, a man) is leaving a British airport, even Heathrow.

According to the Immigration Act 1971, the authorities “reserve the right” to look at those who wear the veil, but it is not a legal obligation. In theory, the airlines should authenticate any passport photograph both as a passenger checks in and at the boarding gate immediately before departure. In practice, though, most companies are reluctant to make what might be considered an insensitive demand of people who are their customers, particularly on routes where it is common for those travelling to be fully covered. Yet if the airlines do not fulfil that task, then impostors would only be exposed if their carry-on baggage were to attract suspicion or if they were caught in a random spot check. Anecdotal evidence suggests that it is rare for security staff to pick out veiled women for inspection.

These rules have to be overhauled completely. It should be a legal requirement that the identity of all passengers leaving Britain is verified properly at check-in, again when boarding passes are presented (normally to representatives of the BAA, the airport operator), then when luggage is being screened and finally just before boarding an aircraft. This should be enshrined in legislation. It is hard to believe that Jama is the only person ever to have exploited political and religious correctness to his advantage in this manner. In the months since PC Beshenvisky was ruthlessly murdered there has been a debate, triggered by Jack Straw, about whether the veil is a “mark of separation” that divides Muslims from the rest of society. Irrespective of where one stands in that argument, everyone should agree that all passengers should be checked properly every day of the year at Britain’s airports.