There are fears that increasing numbers of plates are being stolen or cloned by criminals attempting to commit crimes, or escape motoring penalties.

Superintendent John Wake of the Association of Chief Police Officers Vehicle Crime Intelligence Service told the BBC there was now no confidence in the DVLA licensing system to prevent cloning.

Mr Wake said a registration plate was the "first form" of identification of a vehicle.

"I don't have confidence that beyond that you can identify that that vehicle is the legitimate vehicle for that plate," he said.

He added that the service wants to see a central body set up for registration numbers, and for tamper-proof plates to be fitted in cars.

Paul Watters of the AA agreed that cloning was a "growing problem" that needs to be addressed.

Mr Watters added: "The system does need overhauling, although it would be honest to say we are already moving towards a more secure system."

He cited moves to introduce "theft proof" number plates and to restrict the organisations which are authorised to issue plates.

Nigel Humphries of the Association of British Drivers said he did not believe the problem was with the number plate licensing system.

He said: "What we need is enough traffic police officers to be able to pull people over."