By Daily Mail Reporter
Last updated at 6:12 PM on 29th December 2010

Customs officers at London's Heathrow, the UK's busiest airport, were told not to search potential drug smugglers over Christmas, it has emerged.

An email from the UK Border Agency on December 23 told customs employees at the airport they should 'not actively seek to identify any passenger with internal concealments' due to staff shortages.

The UKBA has now apologised for the edict, which would have allowed mules carrying Class A substances to stroll through the west London airport unhindered.

a customs officer examines the x-ray of a drug mule

An x-ray of a drugs mule showing dozens of capsules inside their stomach. An email from the UK Border Agency on December 23 told customs employees at Heathrow they should 'not actively seek to identify any passenger with internal concealments' due to staff shortages

The email issued by the UKBA and seen by the Sun reads: 'We would seek your co-operation in managing this situation by asking that you do not actively seek to identify any passenger with internal concealments for three days up to and including Christmas Day.'

The email also warned officers that they could be handed a 24-hour shift if any suspected smugglers were arrested at the airport, which routinely handles around 70 million passengers per year.

The UKBA has insisted that the email - which came after 90 per cent of flights resumed at Heathrow following days of winter weather chaos - was not representative of the agency's stance on drug smuggling.

Free-for-all: Drug mules would have been able to stroll through the UK's busiest airport without being checked over Christmas

Free-for-all: Drug mules would have been able to stroll through the UK's busiest airport without being checked over Christmas

Jonathan Sedgwick, the UKBA's deputy chief executive, said: 'This email should never have been sent as this approach does not represent UKBA policy.

'Our aim is to prevent and detect the smuggling of drugs however people try to bring it into the country.'

THE RISKS AND REWARDS FOR DRUG MULES

Drug mules attempting to smuggle concealed narcotics across international borders tend to receive a fee of around 1,000 for their efforts yet their choice could be fatal.

Mules often swallow carefully wrapped packages of drugs or stuff them in to body cavities to keep them hidden as they smuggle them through airport security and across borders.

If plastic pellets or condoms housing valuable consignments of Class A drugs burst in transit, the mules face an agonising death.

A high proportion of foreign females in British prisoners are drug mules from the Caribbean or Nigeria while the majority of smugglers entering the U.S. originate from South America. 

He added: 'Our drug enforcement teams have worked tirelessly over the Christmas period and have successfully intercepted several shipments of class A drugs.

'We need to review what has happened here to ensure that this situation does not arise in the future.'

The security risk at Heathrow comes just three weeks after the UKBA uncovered potential flaws in Manchester Airport's immigration safeguards.

The agency found two areas at the north-west hub where travellers arriving in the UK from overseas could walk out of the airport without passing through customs and immigration checks.

The weaknesses were found during an inspection in May but only publicised at the start of December when the UKBA revealed the security gaps had been brought to the attention of the Home Secretary.

However, the flaws were later removed from the airport risk register to be placed on a regional risk register where they were ignored.

But in an embarrassing development for the UKBA, it emerged some agency staff had known about the 'potential risk to the border' at Manchester airport for some time.