A murder inquiry has been started into the death of PC Jeffrey Tooley, 26, based at Shoreham, Sussex, who had been making routine traffic checks in Brighton Road, Shoreham, shortly before midnight on Saturday. He died from head injuries.
Yesterday forensic science tests were being done on a white Renault van found burnt-out on downs above Hove, Sussex, two hours after PC Tooley was hit.
A police spokesman said PC Tooley and another officer had been making speed checks on a 30mph stretch and PC Tooley was standing in the middle of the road.
"They were using a hand-held laser device on a straight and well-lit stretch of road," said Detective Superintendent Alan Ladley, who is heading the murder investigation.
"PC Tooley was wearing a fluorescent jacket, full protective clothing and carrying a torch. The vehicle was clearly exceeding the 30mph speed limit. It did not stop or brake. The driver would certainly have known he had hit the officer, who was dragged or carried up to 100 yards up the road, and the van would have been damaged."
He appealed for anyone with information about the van - a "traffic van" with a green stripe along the side - to come forward and urged the driver to contact police.
PC Tooley, who was single, had been a policeman for seven years and a traffic officer at Shoreham for more than two years.
"The whole force is saddened and devastated by his loss," said Sussex Assistant Chief Constable Tony Lake. "He was highly regarded by all of his colleagues and he died doing a routine job, a speed check, that hundreds of officers do every day."