Officers from the Roads and Transport Policing Command are appealing for witnesses and information after a cyclist died following a collision with a car in Harrow.
Police were called to Forward Drive, Harrow at 00:04hrs by London Ambulance Service (LAS) on Sunday, 21 June, following reports of a serious road traffic collision.
Officers attended and found a 50-year-old cyclist suffering from serious head injuries.
He was pronounced dead at the scene at 01:03hrs.
The driver of the car, a 30-year-old man, stopped at the scene and was arrested on suspicion of causing death by dangerous driving. He has been taken to a north London police station for questioning.
Officers from the Serious Collision Investigation Unit based at Alperton Traffic Garage are investigating.
Anyone who witnessed the collision or has information concerning the incident is urged to call detectives on 020 8991 9555 or Crimestoppers anonymously on 0800 555 111.