Luxury cars worth up to £400,000 have been stolen from a high-security car park at Gatwick Airport.

It has been reported that keys were left in the cars, under the sun visors, for safety reasons.

An organised gang is believed to be behind the raid, which netted 13 BMWs and Mercedes Benzes from the Summer Special Car Park.

The car park, run by Apcoa independently of the airport, costs £7.40 a day and describes itself as having Gold Standard security. It has barrier control, CCTV and security fencing.

Sussex Police have also accredited the car park with a police standard of safety and security.

Detectives have now launched an investigation to find out how the cars could have been taken from the 6,300-space compound, north of the airport.

Three Mercedes with tracker devices have already been found in South London, although no arrests have been made.

According to national newspaper reports a spokesman for Apcoa said the keys had been left in the parked cars as a safety precaution.

He said faulty wiring could sometimes cause cars to spontaneously catch fire so they needed to be able to move surrounding cars quickly.

No one from the company was available to confirm the reports this morning.

An airport spokeswoman said: "The responsibility for the car park rests with Apcoa, and they are effectively tenants, so we have a limited involvement.

"But we are working really closely with them and the police to find out what happened. We have asked for a full report from the police once they have finished their investigation.

"We will then see what security measures need to be put into effect."

Detectives think the thefts could have been the work of an organised gang.