Shortly after 10:00hrs on Sunday, 25 May, police were called to a north London hospital where a man had been receiving treatment after being found unconscious in Cockfosters Road, Barnet.
Officers from the Serious Collision Investigation Unit are investigating how the 55-year-old man sustained his injuries.
It has been established that the man was in collision with a bus outside Cockfosters underground station at around 23:00hrs on Saturday, 24 May. The driver of the bus did not stop at the scene, apparently unaware of the collision. He has not been arrested.
Following the collision, the injured man remained at the scene for nearly two hours before emergency services were called. During that time, one man helped him from the kerbside onto the pavement and a number of other people approached the man, but they may not have realised the severity of his injuries.
Officers are keen to speak with anyone who may have witnessed the incident as well as anyone who assisted or offered to assist the injured man.
Anyone with information is asked to call officers from the Serious Collision Investigation Unit on 020 8991 9555.
The man has since been transferred to a central London hospital where he remains in a critical condition.
