Police were called at 10:54hrs on Wednesday, 3 November to reports of a moped in collision with a truck at White Hart Lane, N17.
Police, London Ambulance Service (LAS) and London’s Air Ambulance (HEMS) attended.
At the scene the moped rider, a 59-year-old man, had suffered a serious head injury. He was taken by LAS to an east London hospital where he remains in a critical condition.
The driver of the truck stopped at the scene. He was subsequently arrested on suspicion of driving whilst under the influence of drugs. He was taken to a west London police station where he remains at this time.
Closures and cordons remain in place and motorists are advised to avoid the area if possible.
Anyone who witnessed this incident or has information should contact police on 101 or Tweet @MetCC quoting 3542/3NOV21.