A cyclist killed in a crash on Mitcham Road has been named as train driver Neil Turner.
Police are appealing for a significant witness to come forward over the crash, which happened just after 5am on Tuesday July 10.
A man came forward to speak to another witness at the scene shortly after the collision between Mr Turner, who was from Sevenoaks, and a Peugeot 307, but left the scene before giving details to police.
London Ambulance and Air Ambulance service attended but Mr Turner was declared dead at the scene at 5.41am. A post mortem held the next day gave cause of death as serious head injury.
The driver of the car stopped at the scene and no arrests have been made.
The incident is being investigated by the Road Death Investigation Unit based at Hampton. Anyone who witnessed the collision or the events leading up to the collision is asked to contact the witness appeal line on 020 020 8941 9011.