Truth machine means liars must keep a straight face

There are lies, damned lies and imperceptible micro-gestures. Scientists in Manchester are claim they can now detect them with the world's most sophisticated lie-detector.

Using only a laptop computer and a camera, the truth machine condemns the deceitful by spottingmuscle twitches.

A team at Manchester Metropolitan University spent five years developing the device, which detects and analyses thousands of tiny facial movements, many imperceptible to the naked eye. The scientists say it has the potential to screen for hijackers and insurance cheats with unprecedented accuracy.

They claim that tests demonstrated an 80 per cent accuracy rate – against 60 per cent for the traditional polygraph lie detector, which monitors signs of stress such as perspiration, heart rate and voice pitch.

The device, which is being called "Silent Talker", is also much simpler to use and it delivers degrees of lying – complete lie and half-lie.

Dr Zuhair Bandar, the project director, said: "They interviewed the Yorkshire Ripper at least five times [before he was caught]. I am convinced that this is the kind of device which would have told them something was wrong."