By Anna Lindsay BBC News, Poole

Helenor has still not been laid to rest properly

But she died just weeks before her 13th birthday - nine months after going into hospital for a routine examination in 1978.

Her parents, Joan and Derek Bye, from Poole, Dorset, have been trying to lay her to rest properly ever since.

"We are discovering that Helenor's remains have been scattered in eight hospitals," Mrs Bye told BBC News.

The couple now face the "unbearable" task of planning Helenor's fourth funeral.

The whole body had been stripped. Her brain had been removed Joan Bye

It all began in July 1977, when Helenor was taken to Bridgend Hospital in south Wales, where the family then lived, with a suspected bladder infection.

Her parents said that after routine kidney tests, Helenor became extremely sick - hallucinating and showing signs of aggression.

She was diagnosed with temporal lobe epilepsy - something Mr and Mrs Bye never accepted - and was given large doses of the drug Epilim (sodium valproate) to treat it.

Nine months later Helenor collapsed. She was taken to the University Hospital of Wales (UHW) in Cardiff, where her life support was switched off.

Helenor's parents want a public inquiry into their daughter's case

An inquest in 1980 ruled out epilepsy, finding Helenor died of hyperammonemia - a type of ammonia poisoning that caused all her organs to fail.

The coroner said it was genetic, but her parents are adamant that because Epilim was wrongly-prescribed, the condition was triggered.

An investigation by South Wales Police found no evidence of criminal malpractice despite the inquest hearing that the consultant who diagnosed epilepsy, the late Dr Trefor Jones, had suspected "Epilim toxicity".

Dr Jones was also accused by the family's counsel of failing to get a second opinion quickly enough - something he denied.

But it is the information that has been revealed to Mr and Mrs Bye since Helenor's death that has completely shattered their lives.

After thinking they had laid their daughter to rest in 1978 the couple received shocking news in 2001.

Helenor "had a little wicked streak" and would play "funny little jokes"

"We were informed by the University Hospital of Wales that all Helenor's body organs - the whole body had been stripped. Her brain had been removed," said Mrs Bye.

The letter said the body parts were taken for "diagnostic purposes".

Helenor's brain had been taken to the John Radcliffe Hospital in Oxford, and samples had been taken by UHW from Helenor's thyroid, kidney, spleen, heart, lung, adrenal gland, pancreas, thymus and liver.

Body parts remaining after blocks and slides were made were disposed of in 1998, the letter added.

Heartbroken, the couple set about making plans to "liberate" Helenor's body parts from the two hospitals.

In April 2004, they arranged a second funeral.

We had a phone call from South Wales Police to say there were further body parts in hospitals for which we were not aware of Derek Bye

"But we were denied this because South Wales Police classified [the body parts] as clinical exhibits," Mr Bye said.

Last June, there was a further blow.

The couple had been told they could finally collect Helenor's body parts and arranged a third funeral.

"But only days before, we had a phone call from South Wales Police to say there were further body parts in hospitals for which we were not aware of," Mr Bye said.

The third funeral service went ahead but the body parts were not buried because of the news that there were more to collect.

Fourth funeral

From their home in Dorset, where photographs of Helenor adorn the walls, the couple now face the task of planning a fourth funeral for Helenor.

"We are afraid to bring closure on our case now, just in case we have another letter or another phone call to say there are further body parts in other hospitals throughout the UK," Mr Bye said.

"And we are asking - seriously - there has got to be a public inquiry into what has happened to Helenor Bye," her mother added.

South Wales Police said no further criminal inquiries are taking place

A spokesperson for UHW told BBC News it was not normal for a girl to die so suddenly and the coroner at the time had the right to take parts for post-mortem purposes.

But she added: "It is not clear why the body parts were held for so long."

The hospital in Bridgend where Helenor was diagnosed with epilepsy no longer exists.

Sanofi-Aventis, the manufacturers of Epilim, said it wished "to extend its sympathies to Helenor's family for the distress they have suffered".

A South Wales Police spokesman said there were no further criminal inquiries taking place into the case.