For more than 30 years, Ron Smith led a one-man crusade to prove his daughter was murdered.

In a remorseless campaign, which cost him any semblance of a normal life to his dying day, the former policeman, of Guiseley, believed his daughter, Helen, was unlawfully killed in Saudi Arabia in 1979.

But now his battle has gone with him to the grave following his death after years of ill-health and he will never get the answer to his questions of how his daughter, a 23-year-old nurse, died.

Helen’s body was found outside a block of flats in the Saudi city of Jeddah alongside the body of Dutch sea captain Johannes Otten.

A police investigation concluded the pair had plunged 70ft to their deaths from a balcony after an illegal party hosted by one of Helen’s work colleagues, consultant surgeon Dr Richard Arnot and his then wife, Penelope, for whom she had done babysitting favours on her arrival in Saudi.

The Arnots and other guests at the party were questioned in minute detail by police over several months following the tragedy, but the conclusion of the investigation was somehting that Mr Smith never accepted and he began a campaign to prove there was a high-level cover-up amid the scandal caused and insisted his daughter was murdered.

The former policeman claimed there were inconsistencies in the official story and dedicated the rest of his life to discover what he believed was the truth.

He alleged his daughter was assaulted, possibly sexually, and then killed. He also felt Mr Otten had been killed too.

After investigations by officials in Saudi Arabia, stories emerged of a night of alcohol and sexual encounters, but the conclusions drawn into Helen’s death were never altered.

Other members of his family, including Mr Smith’s former wife, Jeryl, wanted to leave well alone. Racked by grief, they decided no matter what happened on that May evening in the Middle East, nothing was going to bring Helen back to life.

But Mr Smith thought differently and it became an obsession.

Whether it was his background as a police officer or just the burning desire to uncover every ounce of evidence and truth about his daughter’s last hours alive, he refused to give in.

Such was his will and determination, he refused to allow Helen’s corpse to be buried for three decades, leaving it lying instead in the morgue at Leeds General Infirmary as he looked for evidence to prove she was unlawfully killed.

The decision earned a place in the record books for the longest period of time a body had been kept without burial or cremation in Britain.

It also helped alienate him from his family as he pushed on with his lobbying for a public inquiry.

Mr Smith did make legal history when Helen’s inquest was held in the United Kingdom in 1982, even though his daughter had died abroad.

At the time, it was billed as the inquest of the century, and it broke new ground in English law as the first instance.

It paved the way for inquests into deaths like that of Diana, Princess of Wales, where a British citizen had died on foreign soil.

The inquest heard Helen suffered some injuries inconsistent with a fall and suffered an unexplained bruise to the side of her head, a broken breastbone and bruises on the inside of her thighs, but an open verdict was recorded.

It failed to satisfy Mr Smith as he relentlessly pursued his cause, pushing unsuccessfully for a public inquiry.

He bombarded Home Secretary after Home Secretary with requests for a public inquiry. Each one failed. Mr Smith produced a 62-page dossier complete with medical statements he said contradicted the explanations given for Helen’s death.

Eventually, with his health deteriorating rapidly and at the behest of his former wife, who lives in the US, and two sons and daughter, Helen’s body was finally cremated in 2009, with her ashes scattered at the Cow and Calf rocks on Ilkley Moor.

But Mr Smith’s fight continued.

His ill-health restricted him to less time poring over accounts of the incident and calls for a public inquiry but he refused to give up, despite spending more and more time in hospital in a new battle against kidney problems.

However, it was to prove a fight he would never win and last week he died at the age of 83.

Mr Smith will be buried at Wakefield Crematorium on Tuesday, April 26.