POLICE investigating the murder of a man whose head swelled to twice its normal size after burns to the face have criticised hospital staff who failed to report the assault for three weeks.

Ambulance crews found Joseph Byrne in a flat at Herschel Crescent, Littlemore, after a caustic liquid had been poured over his head burning his face and neck.

The 61-year-old, of Oxford Road, Rose Hill, told paramedics he had been assaulted and was taken for treatment at the John Radcliffe Hospital casualty unit, Oxford, and later moved to the specialist burns unit at Stoke Mandeville Hospital, Aylesbury.

He suffered a heart attack at hospital, caused by swelling blocking his breathing and died three weeks later after never regaining consciousness.

Police launched a murder inquiry following his death and made one arrest, but failed to secure enough evidence or any witnesses to the assault.

An inquest into his death at Oxford Coroner's Court criticised the hospitals.

Det Sgt Kevin McGuire, who led a police appeal for information, told the coroner's court: "Had we been informed we could have carried out investigations, taken evidence from the address and carried out forensics."

But evidence from the flat at Herschel Crescent was missing after landlords carried out renovations, and no witnesses to an alleged assault in Green Park, Littlemore, were found.

A 42-year-old woman, formerly of Herschel Crescent, was arrested on suspicion of murder but released without charge.

After the inquest, Det Sgt McGuire said: "We're still appealing for information from anybody who might have some information, despite how long ago it happened.

"It was a horrific death directly caused by the malicious application of a caustic liquid and the murder inquiry remains open."

Paramedic Barry Pritchard told the inquest he found Mr Byrne, a former carpenter originally from County Donegal in Ireland, in the flat on May 7 suffering breathing problems. He said Mr Byrne's head was twice its normal size, with his eyes tightly shut and skin stretched tight.

He was taken to the John Radcliffe but died on July 1, 2002, at Stoke Mandeville Hospital after suffering a heart attack and brain damage.

Dr Michael Tyler, from Stoke Mandeville, told the inquest the burns were caused by a caustic alkaline liquid, probably a household cleaning product.

Assistant deputy coroner Dr Richard Whittington said: "The hospitals must have realised they had a public duty to inform police. I will be writing to them to remind all staff of their obligations, because if the investigation started earlier it would have greatly assisted the police."

A John Radcliffe spokesman said staff had no legal obligation to alert police and the patient spent only a brief time in their care before being transferred.

She added: "It was the priority of our staff to ensure he was well cared for and treated in the short time he was with us. We're confident our staff are aware of their public duty to inform police when they think a crime has been committed and we do not feel in this case that our staff failed in their duty."

Jon Fisher, a spokesman from Buckinghamshire Hospitals NHS Trust, which is responsible for Stoke Mandeville Hospital, said staff acted correctly and concentrated on caring for Mr Byrne, which was their "primary duty".

Dr Whittington delivered a narrative verdict.