Beware Fido's stare

LONDON - Dogs that sit down and stare at drug smugglers when they sniff them out are being introduced at British airports.

And a machine that can detect liars by their blushing faces is among measures being undertaken to improve airport security.

The dogs are also being trained to detect large consignments of smuggled tobacco, or of currency being taken out of the country by money-launderers.

The sit-and-stare dogs will replace another type of passive dog that sniffs passengers when they detect unusual substances.

The airports of the future could identify potential terrorists by using a lie detector that spots concealed blushing with a super-sensitive thermal imaging camera.

Liars are betrayed by the heat that rushes to their face when they tell a fib, according to scientists in the United States. Blood flow to the surface of the skin around the eyes increases when someone tells a lie.

The tiny hot spots are invisible to the naked eye but can be measured by thermal imaging.