A motorist hit by a car shortly after he was involved in a fight with another driver at the side of a road has been named by police as Anthony Young.
Mr Young was involved in a row with another driver on Trinity Road in Wandsworth, south west London, on Friday evening.
The 40-year-old from West Norwood, south east London, was then hit by a car that failed to stop.
He was taken to hospital but pronounced dead in the early hours of Saturday.
A post-mortem examination showed he died as a result of a head injury.
Detectives, who originally thought Mr Young was hit by two cars, are searching for the driver who failed to stop.
Scotland Yard Det Insp Justin Davies said: "Although it was late at night we know a number of vehicles drove past the incident and may have witnessed some part of the events.
"We ask any witnesses - whether drivers or passengers - who passed through the area at that time to come forward.
"We also directly ask the driver whose vehicle was in collision with Mr Young to come forward and make themselves known."
The 25-year-old male driver who Mr Young had been rowing with was arrested on suspicion of assault. He has been bailed to return in November.