Police were called at 12:30am on Saturday, 11 November to Court Road in Chelsfield, following a collision involving a grey Audi and a cyclist.
Officers responded with London Ambulance Service and London’s Air Ambulance.
The cyclist, aged in his 60s, was treated at the scene before being taken to a south London hospital in a critical condition.
Despite the efforts of medical staff, sadly he died in hospital a few days later.
His family has been informed and is being supported by specialist officers.
The driver of the car stopped at the scene and is assisting police. There have been no arrests.
Detectives from the Roads and Transport Policing Command are leading the investigation. They would like to speak with anyone who witnessed the collision close to Hewitts Farm, or captured it on dash cam.
Anyone with information is asked to contact the Serious Collision Investigation Unit on 020 8285 1574 or via 101 quoting reference CAD 3081/11Nov.