Detectives have appealed for information after a man was dragged from a vehicle and left unconscious at a petrol station in Enfield.
Officers rushed to the forecourt of a BP petrol station in Bullsmoor Lane following reports that a man had collapsed just after 9am on Saturday.
The man, aged in his 50s, was rushed to hospital where he remains in critical condition.
A man driving a silver Mercedes pulled into the same garage shortly before 5am. He later pulled the victim out of his vehicle and left him on the ground before driving off.
A 42-year-old man has been arrested in connection with the incident after police tracked down the Mercedes. He has been bailed pending further enquiries.
Anyone who was driving in the area before 5am on Saturday morning is asked to check dashcam footage for any material that may assist the investigation.