MURDER squad detectives investigating the "unexpected" death of a Bradford City fire disaster hero are using high-tech voice recognition techniques as they probe whether his death was linked to the care he received.

The crime team is already using the services of a top level geriatrician as part of its investigation into the death of David Hustler.

Mr Hustler, who was awarded the Queen's Gallantry Medal after rescuing two people during the Valley Parade fire disaster, died in hospital, aged 76, at the end of last October following a short unexpected illness.

He was suffering from vascular dementia and Alzheimer's and had been living at Kirklees Council-owned Meadow Green residential home in Dale Lane, Heckmondwike.

Detectives began an investigation into the circumstances leading up to his death after concerns were raised by Mr Hustler's family.

Officers have interviewed staff at the care home and medical experts to establish whether there was any link between his death and the care he received at the home.

A voice recognition expert is thought to have been brought in to help verify what officers have been told.

Mr Hustler's son, David, a 49-year-old builder, said the family was waiting to hear the results of a doctor’s report on the case.

He said: “We are waiting for a final report from the doctor who is helping the investigation, which will then be passed on to the Crown Prosecution Service to decide how the case moves forward.

“I have heard the police mention the possible use of voice recognition software as part of their investigation.”

Detective Superintendent Simon Atkinson, of West Yorkshire Police's Homicide and Major Enquiry Team, who is leading the investigation, confirmed that voice recognition techniques were being used as part of the overall investigation.

Det Supt Atkinson said he could not comment on how they were being used on the specific inquiry.

But he added: "In general terms, voice recognition techniques could be used, for example, when you are trying to establish who is speaking in a conversation. We would get a recording of that person and take it to an expert to establish who is speaking."

Det Supt Atkinson said the police file had been passed to an expert geriatrician, specialising in the care of the elderly, for them to consider the actions of the staff caring for Mr Hustler. The file is then likely to be passed to the Crown Prosecution Service.

Det Supt Atkinson said: "The expert is looking at all aspects of Mr Hustler's care and treatment to see if it was appropriate in the circumstances. He is one of the best in the business.

"He has been given very comprehensive terms of reference, covering Mr Hustler's care and treatment and the circumstances that led up to his death. When we have his findings we may then refer matters to the Crown Prosecution Service."

He added: "This investigation is covering all possible aspects. It is a difficult time for David Hustler's family. Rightly, they want some answers as to how their loved one died, and that's what we are attempting to do."

Simon Hustler, who lives in Halifax, praised the work of West Yorkshire Police in the ongoing investigation.

He said: “I’ve got no issues with the police, they are doing a fantastic job so far, and the fact it has taken this long is not a problem. It is better that the investigation is done thoroughly than quickly.

“We just want what is right. If there is a criminal case to answer, the police need to have the evidence to take the case forward, which we understand takes time.

“But we have no issues with the police, they are doing a great job.”

Mr Hustler, a grandfather, who was formerly of Shipley, died at Dewsbury and District Hospital, on Wednesday, October 28, last year.

At Valley Parade, on the fateful day of May 11, 1985, Mr Hustler saved Kathleen Kelly from the fire, before bravely running back into the blazing stand to rescue teenager Matthew Wildman. Mr Wildman was on fire and Mr Hustler put his arms round him to put out the flames and then helped to take him out of the stand.

Mr Hustler himself suffered burns during the rescues and his story was later featured in One Day In May, a documentary about the Valley Parade fire.

His funeral, in January, which took place at Nab Wood Crematorium at Shipley, was well attended and mourners included Mr Wildman and the Lord Mayor of Bradford, Councillor Joanne Dodds.

Mr Hustler, a lifelong Bradford City supporter, helped to raise funds for the Burns Research Unit. He was a regular volunteer with special needs group The Wednesday Leisure Club, a volunteer carer and coach for the GB Special Olympic ten pin bowling team, and was honorary chairman of Great Horton Church Cricket Club.