The owners of high-performance cars in Birmingham have been urged not to keep the keys in their bedroom at night to avoid being confronted by burglars.

West Midlands Police said there had been a spate of “car key burglaries” across the city, Solihull and the Black Country in recent weeks.

Traditionally, thieves break into homes in the night looking for the keys to luxury cars that are parked on driveways outside. They have been forced to become more brazen because modern anti-theft devices fitted to new vehicles mean that they cannot be stolen without their keys.

Police said they were issuing the advice as they wanted to avoid homeowners being terrorised at night by thieves hunting for keys.

“Because it is the car keys the thief wants, when at home at night do leave them downstairs,” the force suggested.

“We advise not to take them with you when you retire to bed. It’s the keys they want, not you.”

Insp Sharon Naughton, from the force Criminal Investigation Department, said: “We are currently experiencing an increase in the theft of high-end, high performance sports cars.

“Advances in security methods can make it difficult to steal cars so a thief may first enter a home in order to obtain the car keys.”

“We are advising people to be security conscious, as this type of crime can be prevented.

“If you have a garage, please use it and never leave your car keys on show through your letter box or ground floor windows.

“In the unfortunate and unlikely event a thief breaks in to steal car keys, it’s best the keys are still kept down stairs for the safety of the inhabitants.”

She added: “Officers across the force are working to effectively tackle this crime and we are making good progress but people still need to think about their own security.”

Last month wealthy owners of high performance cars such as BMWs, Audis and Jaguars were warned to be on their guard after thieves targeted Millionaire’s Row of Little Aston, Sutton Coldfield.