London Heathrow Airport has been hit by further controversy with news customs staff were told not to stop suspected drug smugglers in the run-up to Christmas because of a lack of resources.

With the airport reeling for a raft of cancellations caused by snow, staff at the airport were requested to help “managing the situation” and instructed not to “actively seek to identify any passenger with internal concealments”.

The instructions cover the period from December 23rd-25th, when disruption caused by snow was at its peak.

The revelations were revealed in a leaked email from UK Boarder Agency officials.

Following the release UKBA chief Jonathan Sedgwick admitted the e-mail should not have been sent.

He added a review would be held so the matter “does not arise in the future”.

Heathrow Strife

The news is just the latest in a string of events to blight the airport – branded as the busiest in Europe – over the festive season.

Hundreds of flights were cancelled in the run up to Christmas day as supplies of de-icer were exhausted.

Reports suggest the total financial cost to the airport could total £40 million, roughly equivalent to the figure lost during the Icelandic ash crisis earlier in the year.

Transport secretary Phillip Hammond has since called for financial penalties to be imposed on airport operator BAA in response to the crisis.

Hammond accused BAA of failing to prepare adequately for the poor weather conditions.

Investors in Madrid reacted badly to the news, with shares in BAA owner Ferrovial falling sharply earlier in the week.

However, the Spanish company is playing down suggestions the problems could harm plans to sell a ten per cent stake in BAA.

A successful sale would cut its majority shareholding to below 50 per cent and remove BAA’s €13bn debt from the group’s balance sheet.