Threatened with a ticket, a Russian motorist trapped a traffic policeman's hand in his car window then drove off with the officer attached, police said on Tuesday.

The policeman was dragged along the road beside the BMW saloon for five metres (yards) until a second officer in a patrol car blocked the motorist's path, said a traffic police spokesman.

"We have opened a criminal case on charges of ... using force against an official," said the spokesman. "The officer's injuries were not too bad but he is still on sick leave."

The motorist, a Moscow property developer, told Izvestia newspaper police had invented the incident. He said a business rival with connections with the police was trying to set him up.