Police say the victim was cycling across the pedestrian crossing outside Brixton Tube station when he was hit by a dark or black car.
We need to locate the car involved and speak to the driver as soon as possible. The victim was left lying in the road having suffered very serious injuries.
I would urge anyone who witnessed the collision or has any information, regarding the identity of the driver or whereabouts of the car to contact the Hampton Traffic Unit on 020 8941 9011 or Crimestoppers anonymously on 0800 555 111.
More top news
Arsenal managed to beat Everton at the weekend but it wasn't enough to finish in the top for the first time in Wenger's time at the club.
The entertainer was held for the murder of Stuart Lubbock, who was found dead in his swimming pool in 2001, but never charged.
Although the diamond was believed to be cut in the 19th Century, its history and how it arrived at the car boot sale is unknown.