Drivers who use motorway service stations are being urged to check that their cars are locked after a spate of thefts believed to be linked to jamming technology which prevents them from locking remotely.
Thames Valley Police have said there have been 14 thefts from cars at motorway services in Berkshire along the M4, at three different service stations, and have urged people to remain vigilant and check cars are locked.
In each case there was "no obvious sign of a break-in" and no damage caused to the vehicles, but items such as tools, suitcases, laptops, and cash were taken from them.
It is believed that the thieves used radio jammers which can interrupt the signal sent by remote keys, meaning that the cars are not locked properly and can be plundered without any sign of a break-in.
The three service stations are Chieveley Moto Services, Reading Moto Services, and Membury Welcome Break, all of which have had multiple thefts reported between 24 November and 1 December.
Investigating officer, Sergeant Alan Hawkett of Newbury Police Station, said: "I strongly recommend that any members of the public visiting motorway services stations anywhere in the country keep all valuable items in their possession when away from their vehicle.
"Offenders may be using technology to prevent your vehicle from locking therefore we would advise a manual check of the doors before leaving your vehicle."
Sergeant Hawkett has also urged members of the public who have dash cameras installed in their cars and were at the service stations between those dates to get in touch.
"You may have captured an offence or offender on camera," he said. "I am extremely keen to review the footage."