DETECTIVES were last night trying to discover how a young man received injuries that left him fighting for his life.

Lee Walker, 22, suffered serious head injuries during a night out with friends in Darlington on Monday.

Although what happened is a mystery, it is believed he may have been the victim of a beating in the Skinnergate area after he left a pub.

Mr Walker, who lives with his parents in the Cockerton area of the town, managed to stagger home, but later collapsed and was taken to Darlington Memorial Hospital.

He was on a life support machine at Middlesbrough's James Cook University Hospital last night, with his family at his bedside.

Yesterday, police sealed off part of Skinnergate as forensic teams hunted for clues.

An area adjoining the nearby indoor market was also cordoned off as DNA swabs were taken from bloodstains on the ground.

Other areas around the town centre were checked for bloodstains, so police could piece together the route Mr Walker had taken.

Police said he and three friends went out drinking after work, visiting a number of pubs.

At one stage, he and his friends met up with two girls, and some time after 9pm, they went to the Barsize pub, in Skinnergate.

While the group were in the pub, one of them - not Mr Walker - was caught up in a disturbance, knocked over a table and was asked to leave.

Mr Walker followed his friend outside and was found unconscious in the street shortly afterwards by a member of the group.

The friend who found him and a stranger managed to bring Mr Walker round and lift him to his feet.

The three went back into the pub, but Mr Walker and his friend were asked to leave.

At about 11pm he arrived home where he was said to be talking and behaving out of character.

He was later found collapsed in the bathroom and was helped into bed, where his mother monitored his condition.

Shortly after 5am, he was discovered slumped on the bedroom floor and was taken to Darlington Memorial Hospital before being transferred to James Cook University Hospital.

Despite rumours that the incident had been a stabbing, police last night confirmed that it was not.

Detective Superintendent Harry Stephenson, who is leading the investigation, said Mr Walker had left the Skinnergate pub fit and well and minutes later he was found lying unconscious outside.

He said: "While I have to keep an open mind on what might have happened to Lee, I cannot rule out that he was the victim of an assault.

"Officers are currently studying footage from closed-circuit television cameras in the hope it will help establish what exactly happened.

"In the meantime, I would like to speak to anyone who was in Skinnergate between 9.30pm and 10pm on Monday night who may have witnessed any arguments, scuffles or fighting outside the Barsize public house or in the alleyways leading to Mechanic's Yard and Buckton's Yard.

"What they saw could be vital to this inquiry.''

Anyone with information is asked to telephone Darlington police on (01325) 467681, or Crimestoppers on 0800 555111.