The initiative has been launched in an area where theft from cars has been rife.

"We have had a bit problem with thefts from cars, so we decided to be a bit more innovative," said Superintendent Jim Davis, the officer behind the initiative.

If items are needed urgently, police will return the goods immediately.

"We want to stop people from being the victims of crime," he said. "We are not talking about £3 in loose change in the glove compartment, we are talking about cameras, laptops and expensive leather jackets. People would be far more upset if their property really was stolen."

Police are only removing items from unlocked cars. Where they see either an unlocked car or valuables left exposed in a locked vehicle, owners are being sent a letter advising them to take better care or their property.

The initiative was welcomed by the AA. "It would be quite irritating for motorists to come back to their car and find that items have gone missing. But on reflection they may think it is better that the stuff has been taken by the police rather than local thieves.

"I would imagine police patience is wearing thin and there have been other projects where they have set up cars as decoys and caught thieves.