Detectives are appealing for witnesses after the victim of a collision died in hospital.
At 11:00hrs on 29 December 2017, officers on patrol came upon a collision between a black cab and a pedestrian on Horseferry Road close to the junction with Medway Street in Westminster.
The man was taken by the London Ambulance Service to a central London. He died on Saturday, 6 January.
He has been named as 67-year-old Robert Smith from Westminster. His next of kin are aware.
A post-mortem examination will be held in due course.
The driver of the taxi stopped at the scene and is assisting police with enquiries.
Detectives from the Met's Roads and Transport Policing Command are investigating. They would like to hear from anyone who witnessed the collision and who is yet to speak with police.
Anyone with information is asked to contact the witness appeal line on 020 8543 5157.
There have been no arrests and enquiries continue.