Officers were called by LAS at 8.55pm on Saturday, 11 January to Falcon Road, junction with York Road SW11, following reports of a road traffic collision.
Two cars had been involved in a collision. A third party, a pedestrian aged in his 60s, was injured and pronounced dead at the scene.
Police have informed his next of kin.
One of the drivers, a 32-year-old man, left the scene on foot but returned a short time later.
He was arrested on suspicion of causing death by dangerous driving and failing to stop at the scene of a collision. He has been taken into custody.
The other driver, a 29-year-old man, was not arrested and is assisting police with their enquiries.
Road closures were in place but have since been lifted.
Alternatively call 101 or tweet @MetCC, quoting CAD 6988/11 Jan.