BRITAIN'S most prolific car thief who was on the run from prison has died in a head-on crash in a stolen car.

Obsessive Colin Sadd, 44, was branded "the North's most dangerous car thief" and notched up a 155 previous convictions.

He hit the headlines when it was revealed he would wash and polish the stolen vehicles, clean the interior, and leave the cars to be returned undamaged to their owners.

The contract cleaner was described by one judge as "aptly named" and by another as "the man you would most want to steal your car".

He was serving a sentence at Kirklevington Prison, near Yarm, Teesside, and was on day release in December when he failed to return.

It emerged yesterday that he hit a 7.5-tonne lorry as he tried to steal a Vauxhall Astra from a garage near Preston, Lancashire, on Friday.

A police spokeswoman said that Sadd had posed as a prospective customer at Direct Vehicle Sales, in the village of Much Hoole.

She said: "He was talking to the sales staff, and when they were distracted he stole the keys to one of the cars and started a Vauxhall Astra.

"The man accelerated out on to the A59, directly into the path of a vehicle, and was pronounced dead at the scene."

Sadd, who had an encyclopaedic knowledge of cars and their specifications, was jailed for six years in Sheffield, in 2004, after admitting stealing two cars, and asked for 31 similar offences to be taken into account.

The court heard he had 155 previous convictions and suffered from a compulsive disorder, which led him to clean and polish the cars he took before leaving them spotless by the side of the road.

Sadd, who did not own a car, once wrote from his prison cell to North-East dealer Reg Vardy, claiming he needed information for a "special project" on top cars.

He wrote: "My only gain has ever been that of enjoyment in driving some of the best cars in the world."

Sadd, from Sheffield, began his car-stealing career at the age of 11, after spending a troubled childhood in care.

On each occasion, Sadd, dressed in a suit, posed as a businessman and took the cars on test drives from garages, but never returned.

A court once heard how Sadd was trapped in York when he returned to a Carwise UK showroom, in James Street, where he had already been, and aroused the suspicions of boss Robert Emmerson.

Arrested and interviewed by police, Sadd said he had gone to York specifically to take a Ford Sierra.