Finnish electronics firm VTT has unveiled a biometric security system for mobile phones that operates by measuring the user's gait.

The device, which contains movement sensors, connects to a phone and is calibrated so that it recognises the unique walking pattern of its owner.

Each time the phone is used it compares the gait of the user with that held in memory. If there is a mismatch the user is locked out of the phone and must provide password details to use the handset.

VTT claimed that the device had achieved 90 per cent accuracy in tests. The firm now hopes to adapt the technology for use with laptops and credit cards.

Mark Needham, managing director at mobile device firm Widget, said: "I have never heard of anything like this.

"We used to sell PDAs with fingerprint control but they weren't very popular so I don’t know how much demand there would be for this. Fingerprint control would seem more appropriate but you don't hear of people asking for it."