A large section of St Aldates in Oxford was cordoned off this morning after a man, thought to be a motorcyclist, was found last night suffering serious head injuries.

The man, who has not been identified, was taken to the John Radcliffe Hospital in Oxford after being found in the street about 10pm by a member of the public.

Thames Valley Police are now trying to establish how his injuries occurred.

A police officer at the scene, close to the junction with Speedwell Street, said officers were trying to establish if a crime had taken place.

A spokesman for South Central Ambulance said: “About 10.15pm, we received a call from a member of the public to say that a man had been assaulted.

“Our staff found a 44-year-old man suffering head injuries, and he was taken to the John Radcliffe Hospital.

“He was conscious when our staff arrived but then he went unconscious.”

The man's condition was described last night as serious.