Officers from the Metropolitan Police were called on December 3 with reports of a crash in Beauly Way.
They were dispatched to the scene with London Ambulance Service paramedics where an 81-year-old man was found injured.
He was treated at the scene before being taken to hospital.
He died three days later on December 6 with his family members present.
They are now being supported by specially trained officers.
The driver of the car stopped at the scene and has been assisting police with their enquiries.
An investigation is underway by the Roads and Transport Policing Command who would like to speak with anyone who witnessed the crash or who captured it on dash cam or CCTV.
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Det Sgt Rob Groombridge said: “The police investigation is ongoing and officers are working to obtain CCTV and other footage that is essential to the investigation.
“I am appealing for anyone who saw the collision but has not yet to spoken with police to contact us.”
Anyone with information is asked to call the witness appeal line on 020 8597 4874, or via 101 quoting CAD 5212/03Dec.
