A murder hunt has begun in Oxford after the death of a man, believed to have been doused in corrosive chemicals.

Joseph Byrne, pictured, of Herschel Court, Littlemore, died in Stoke Mandeville Hospital, near Aylesbury, on Saturday, three weeks after he was admitted to the John Radcliffe Hospital, Oxford, with burns to his head and neck.

A post-mortem examination carried out by a Home Office pathologist revealed that Mr Byrne, 61, died of a heart attack brought on by his injuries.

Det Supt Steve Morrison, who is leading the investigation, said: "The victim in this case was well known in Oxford. He lived on the streets in the city for many years, but had moved into a flat in Herschel Court with his partner some time before his death.

"We believe he was involved in an altercation with at least one man on a triangle of grass at the junction of Cowley Road and Long Lane on Sunday, May 5, the day before he was admitted to the JR.

"We want to speak to anyone who witnessed this altercation, or who has any information which could help us identify the person or persons involved in the dispute."

Police think the chemicals, which appear to have been some sort of alkaline solution, that caused the victim's burns were then thrown over him.

Anyone with information should call Oxford police on 01865 266333, or Crimestoppers on 0800 555111.