CAR sellers are advised to be wary of bogus car buyers swapping key fobs in order to steal vehicles.

Detectives have seen two scams recently in which high value cars advertised for sale on AutoTrader have then had their keys substituted by visiting conmen.

In an incident on September 18, a BMW X5 was stolen from outside a property in Churt after fake buyers used a similar method of distraction to swap car keys.

Later on that evening the car was driven away across a neighbour’s garden but was later recovered on the A3.

In the latest incident a black convertible Mercedes Benz E220 in the St John’s area of Woking was advertised and two men went to view the vehicle, on September 23.

While scrutinising the car one of the men asked the owner for the manual key to check it was working. The Mercedes had an electronic fob with a metal key which can be used manually in case of electronic failure.

The seller later discovered the remote key would not operate and was a different one to the original handed over to the buyer.

She alerted police and as a result patrols in the area were stepped up.

Investigating detective Mike Taylor is urging anyone who is selling a car either online or in traditional publications to be aware of the distraction technique.

He said: "There is a very clever distinctive scam happening in which rogue buyers are removing a set of keys and replacing them with another set which does not work.

“The offenders are then leaving with the functioning set and plan to return to steal the vehicle. Please don’t be conned in this way and don’t handover keys to an unknown person, instead demonstrate how they work yourself.

“If you have any suspicions about the legitimacy of a would-be purchaser please follow your instincts, keep hold of your property and call Surrey Police.”

A 33-year-old man has been charged in relation to the Churt offence. Martin Macdonald of no fixed abode has been charged the theft of a car and having no licence or insurance. He is currently remanded in custody and is due to appear at Guildford Crown Court on Thursday, October 15.

Four more men are currently on bail in relation to the two incidents. They are due to report back to police in November.