Drivers using motorway services are being warned to check their cars are secure after a spate of thefts believed to be linked to technology that stops them remotely locking.
Thames Valley Police said there had been 14 recent thefts from cars at motorway services in Berkshire and, in many cases, there was "no obvious sign of a break-in and no damage caused to the vehicles as items were stolen from them".
It is believed that thieves may have used radio jammers, which can interrupt signals sent by a remote key, to plunder the vehicles undetected.
Items such as a laptop, suitcase, wallets and luggage had been stolen during the break-ins, and police have advised motorists to do a manual check before leaving their car unattended.
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."