A man in his 40s is in a life-threatening condition in hospital after a collision with a car outside Oxford’s Magdalen College.
Police said the pedestrian and a black Toyota Prius were involved in the collision in the city’s High Street at about 02:40 GMT on Friday.
They asked anyone who saw a man carrying a guitar in the area at around that time to get in touch with officers.
A lorry driver thought to have been in the area at the time is being treated as a witness and is also encouraged to come forward.