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

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

But now the 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 70 feet to their deaths from a balcony after an illegal party hosted by one of Helen’s work colleagues.

It was an explanation Mr Smith never accepted and he began a campaign to prove there was a high-level cover-up 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 said 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 nothing was going to bring Helen back to life. But Mr Smith thought differently and it became an obsession.

Gazette & Observer editor Malcolm Hoddy, a freelance agency reporter at the time, was the first journalist to interview Mr Smith.

He said: “In my 45 years as a journalist I have worked on all types of stories at local, national and international level. I cannot think of another story which has had so many twists and turns. Many views were expressed about Ron – but all I know is that he was a dad who wanted to know the answer to the simple question of how his daughter met her death. He was prepared to sacrifice everything in a bid to get to the truth.”

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 UK 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. It paved the way for inquests into deaths like Diana, Princess of Wales, where a British citizen 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 claimed contradicted the explanations given for Helen’s death.

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

Mr Smith’s fight continued, however.

Ill-health restricted him to less times 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 with kidney problems.

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

A sad end to a tragic case, where the full truth is unlikely ever to be revealed.

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