Officers were called to Walton Road at 4.41am on Wednesday, July 23, following reports of a body.
Paramedics from the London Ambulance Service also attended.
The man, believed to be in his 50s, was pronounced dead at the scene.
A crime scene has been established on Walton Road and extended into nearby streets while police investigate the circumstances.
A spokesperson for the Metropolitan Police confirmed that the death is being treated as category 3 – sudden and not expected.
A post-mortem examination will be arranged.
Anyone with information is asked to call 101, quoting CAD 1022/23JUL.
To remain anonymous, contact Crimestoppers on 0800 555 111 or visit crimestoppers-uk.org.
