Can you tell these two people apart?

U.K. airport face-recognition scanners can't.

In a leaked memo, an official says the machines have been recalibrated to an "unacceptable" level meaning travellers whose faces are shown to have only a 30 per cent likeness to their passport photographs can pass through.

The machines, undergoing trials at Manchester airport, have apparently been questioning so many passengers' identities that they were creating huge queues...

Rob Jenkins, an expert in facial recognition at Glasgow University's psychology department, said lowering the match level to 30 per cent would make the system almost worthless.

Using facial recognition software from Sydney airport in Australia set at 30 per cent, he found the machines could not tell the difference between Osama bin Laden and the actors Kevin Spacey or even the actress Winona Ryder while Gordon Brown was indistinguishable from Mel Gibson.

The Home Office begs to differ:

"Previous tests show that the system can reliably pick out imposters and even distinguish between identical twins."

Yeah, right.