Police were called to Southborough Lane in Bromley around 1.20 am on Sunday, 18 July following reports of a collision involving a car and an e-scooter.
Officers attended with London Ambulance Service paramedics and found a 16-year-old male, who had been riding the e-scooter, with serious injuries.
He was taken to a central London hospital where he sadly died.
The driver of the car involved in the collision, a red Fiat Punto, did not stop at the scene.
It was discovered later the same morning in Southwood Close, Bromley.
The driver, a 20-year-old man, was arrested on suspicion of failing to stop at the scene of a collision, causing death by dangerous driving and providing a positive alcohol breath test. He was taken into custody where he remains.
Officers are also investigating the disappearance of the e-scooter that was being ridden at the time of the collision. It is believed to have been stolen from the scene.
Anyone who saw the collision, witnessed the removal of the e-scooter, or who saw a red Fiat Punto being driven in the area at around 1.20am, is urged to call police on 0208 285 1574, providing the reference 775/18JUL.
Information can also be provided to Crimestoppers, anonymously, by calling 0800 555 111.
Local residents are also urged to check doorbell video cameras and drivers who were in the area are asked to look back on dash-cam footage, to see if they have captured anything related to the collision or the vehicles involved.