Full body scanners will be introduced at Heathrow Airport by the end of this month.

The government will also introduce more frequent searches, behavioural analysis and more sniffer dogs.

It is also considering the introduction of passenger profiling, Home Secretary Alan Johnson confirmed.

The introduction of the extra security measures are a direct result of the failed Christmas Day bomb plot.

The extra security measures will inevitably lead to yet more delays at the UK’s busiest and most congested airport.

It is not yet clear whether the enhanced security will be introduced at other UK airports.

In an address to the House of Commons, Johnson said:

“No one measure will be enough to defeat inventive and determined terrorists and there is no single technology which we can guarantee will be 100% effective.

“We are examining carefully whether additional targeted passenger profiling might help to enhance airport security.

“We will be considering all the issues involved, mindful of civil liberties concerns, aware that identity-based profiling has its limitations, but conscious of our overriding obligations to protect peoples’ life and liberty.”

Heathrow operator BAA said it would try to avoid “unacceptable delays” to passengers.

A spokesperson for British Airways said: “We have not issued any new instructions so far. It is something we will need to look at.”

Since Monday, BAA has been using extra staff trained in detecting unusual behaviour to identify passengers who might face extra security checks.

There are three types of body scanners available which vary in strength and their ability to detect artificial substances.

It is not clear which one BAA will introduce but it indicated scanners would be in place by the end of the month.

The move was sparked by Umar Farouk Abdulmutallab, a former student at University College London, who allegedly attempted to ignite explosives hidden in his underpants as a flight from Amsterdam came in to land at Detroit on Christmas Day.

Mr Johnson confirmed Abdulmutallab, the son of a wealthy Nigerian banker, was known to MI5 during his time in London but he said he was not “engaged in violent extremism”.