POLICE are urging the fleet industry to be on its guard against criminal gangs who are stealing millions of pounds worth of cars from leasing firms and dealers. Thieves have been phoning leasing firms pretending to be police investigating vehicle accidents, asking for door key numbers - and then getting the keys cut and stealing the cars.

The caller pretends the number is needed to help release injured drivers trapped in a vehicle. 'It is a widespread and deeply worrying problem,' said a senior police officer, who asked to remain anonymous to protect the location of his station, which is currently investigating a local gang.

Official warnings have been sent by the police to major leasing firms and dealer networks. As a result, Lex Vehicle Leasing has issued a security directive to its staff in a bid to protect its 73,000 vehicles. It says: 'If the police phone asking for information, you should always phone them back with the information. The number they give you should be a main switchboard and not a direct line.

'If a fleet administrator phones for any information you must ask them to fax us the request on headed paper. If a driver calls, they must do the same - if they cannot do it via their office because they have locked the keys in the car then they should ask a garage to fax, again on headed paper. If any of these people complain about having to fax, point out that it's for their own security.'