Linda Stilwell (left) and Derek Percy.
An inquest into the 1968 death of seven-year-old Linda Stilwell will be reconvened after the Victorian Court of Appeal ruled a certificate of immunity should have been offered to the suspect killer, Derek Percy, to give evidence.
Linda disappeared on August 10, 1968. She was last seen near Luna park in Beaconsfield Parade, St Kilda. Her body has never been found.
At the insistence of Linda's mother, Jean Priest, an inquest began into her death in December 2009.
During the inquest, Mrs Priest sought to rely on numerous statements from police, a forensic pathologist and a psychologist which her lawyers argued tended to demonstrate that child-killer Derek Percy was responsible for her daughter's death.
The statements related to the death of a child whose murder Percy had been acquitted of by reason of insanity, and to the abduction, mutilation and deaths of several other children.
The coroner ruled that the statements were irrelevant to the inquest and they were ordered to be removed from the brief of evidence.
Percy was called to give evidence at the inquest but he objected on the grounds his evidence might incriminate him.
The coroner ruled that there were reasonable grounds for the objection and Percy was not compelled to give evidence, partly due to not being confident of the reliability of evidence.
But the coroner did not inform Percy that if he gave evidence he could be granted a certificate of immunity from prosecution.
The inquest was subsequently adjourned so Mrs Priest could challenge the rulings at the Supreme Court.
The challenge was dismissed, so Mrs Priest took her fight to the Court of Appeal.
On Thursday, Court of Appeal President Chris Maxwell and Justices David Harper and Pamela Tate ruled in her favour.
The judges stated that that Deputy State Coroner Iain West was obliged to take into account most of the statements relied on by Mrs Priest as relevant to the inquest into her daughter's death.
ABOVE: Derek Percy (left) who is suspected of involvement in the murder of the Beaumont siblings (top right) and Linda Stilwell.
It also held that the Coroner was obliged to take into account the most recent medical evidence relevant to the issue of the reliability of Percy's short-term and long-term memory.
In addition, the Court of Appeal held that the coroner was obliged to inform Percy that if he gave evidence willingly he would be given a certificate of immunity and the effect of such a certificate.
The judges directed that the inquest be reconvened and conducted according to law.
Percy, who is Victoria's longest-serving prisoner, is in jail indefinitely for the mutilation killing of Yvonne Tuohy and he is suspected of involvement in up to seven other child murders including Australia's most high-profile cold case, the Beaumont children.
The three siblings, Jane, 9, Arnna, 7 and their brother Grant, 4, disappeared from Glenelg Beach near Adelaide, South Australia on Australia Day, 1966.
They were last seen in the company of a tall, blond man, of thin to athletic build aged in his mid-30s.
Percy's insanity plea in the Tuohy murder was partly based on a psychological condition he claims to suffer that can prevent him from remembering details of his actions.
He is believed to have indicated that he might have killed the Beaumont children, as he was in the area at the time, but he has no recollection of actually doing so.