Police are clamping down on petrol thieves - some of whom modify their vehicles to take up to 120 litres of fuel.

Hartshead Moor Service Station on the M62 has been targeted by fuel cheats who are - according to police - striking every couple of days now.

Police are patrolling the service station and parking on the forecourt to deter people from driving off without paying.

Inspector Pete Brennand of Brighouse police said: "I have heard of cars that are equipped especially to steal petrol. They have extra tanks in the sides or floor panels. Unfortunately attendants don't always register that 100 or 120 litres is going into a vehicle that couldn't possibly hold that, before they drive off.

"Whenever we have been up there with our car, nothing has happened. But when we're not there it's happening every couple of days."

Insp Brennand said the Welcome Break service station was a prime location for this type of crime because the culprits can escape into motorway traffic in seconds.

He said the station did have CCTV, but it was out-dated and they were hoping the station would consider upgrading it.

"This problem is easily solved," he said. "If you ever go into Wakefield, you cannot buy petrol without paying for it first, or putting your credit card in a machine before it will release any fuel. That system should be introduced at Hartshead.

"There will always be a minority who genuinely forget to pay for their petrol before driving off, but there is a clear majority who go in with no intention whatsoever of paying."

He said there was no pattern to the problem, which was occurring on both east and westbound carriageways at different times of the day and night.

"It is a pure guessing game when it will happen," he said. "We compared the statistics with Ferrybridge Services on the A1/M62 and they had similar statistics. But these crimes affect our crime statistics in Brighouse."

Insp Brennand said the police had liaised with staff at the service station to give them crime prevention advice and it was now up to the service station to act on that advice to stop the problem escalating any further.

Service station manager Jeff Hawley declined to comment.