VIDEO: CCTV of thieves stealing a vehicle without the key by using a relay box

Police have released what is believed to be the first footage of a 'relay crime' where criminals can drive off with cars without the owner's keys.

The footage shows two men pull up outside the victim's house, holding a relay box, which is a device used to receive signals through walls, doors and windows, but not metal.

One man can be seen waving a relay box in front of property, the box receives a signal from the key inside and transmits it to the second box next to the car.

The car's locking system is then tricked into thinking the car key is unlocking it, allowing access to the vehicle.

The thieves then drive off with the Mercedes, with the whole crime only taking one minute to complete.

Mark Silvester, from the Police crime reduction team, said: "To protect against this type of theft, owners can use an additional tested and Thatcham-approved steering lock to cover the entire steering wheel.

"We also recommend Thatcham-approved tracking solutions fitted to the vehicle.

"It is always worth speaking to your main dealer, to ensure that your car has had all the latest software updates and talk through security concerns with them."

Sgt Tim Evans said: "It's important the public are reassured that we are taking proactive steps to tackle this type of crime.

"We hope that knowledge of this type of crime will enable members of the public to take simple steps to secure their vehicle and assist us."