A murder investigation has been launched following the death of Darlington student Lee Walker.

The 22-year-old had been in a critical condition since his admission to hospital in the early hours of Tuesday morning.

He had been found lying unconscious in the street outside Barsize pub in Darlington's Skinnergate at about 10pm on Monday night.

A post-mortem carried out late last night by Home Office pathologist Dr Mark Egan confirmed that Mr Walker had been the victim of an assault which had resulted in the head injuries which subsequently caused his death.

Detective Superintendent Harry Stephenson is leading a team of 40 officers working in an incident room at Darlington Police Station.

He said Mr Walker had arrived at Barsize with a group between 8pm and 9pm, after which one of his friends was involved in an altercation and escorted from the premises.

Mr Walker went outside shortly afterwards when it is believed he was attacked.

Police studying CCTV footage would particularly like to speak to a group of three or four people who approached the bar and appear to have seen something in the street before entering.

Anyone with information is asked to contact the incident room on (01325) 467681, or anonymously to Crimestoppers on 0800 555111.