CCTV footage has emerged of the moment a motorcyclist knocked over a pedestrian and yelled at him before driving off.
In the 44-second video the pedestrian crosses the road as the traffic starts to move. Before he can make it to the other side, he is struck by the motorcycle. The collision sends both the rider and victim hurtling several feet along the street.
The motorcyclist gets off his vehicle but instead of helping the fallen man up, he yells at him then gets up and exits the scene. The victim is left lying prostrate in the middle of the road.
The hit-and-run happened shortly after midnight on 28 February at the Malden Road at the junction with London Road in Sutton.
The motorcyclist was briefly pursed by a driver, who saw the crash and followed the man in his car.
The 53-year-old victim was taken to hospital and treated for his injures which are not life-threatening.
The police are appealing for witnesses and asking for the driver of the car to get in touch.
Detective Sergeant Dave Jarvis of Sutton Police said: "It would have been obvious to the rider of the motorcycle that the pedestrian he had collided with was seriously injured."
"To act in the way he did, shouting at the unconscious man and driving off from the scene without attempting to seek medical help, was a truly heartless act."
Anyone with information should contact Sutton Police on 101 or can anonymously contact Crimestoppers on 0800 555 111.