The family of missing backpacker Tony Jones hopes a Queensland court ruling will finally open the way to solving his disappearance almost 40 years ago.
Mr Jones mysteriously vanished near Townsville in November 1982 while hitchhiking to Mount Isa.
The 20-year-old's body has never been found but a coronial inquest in 2002 ruled he'd probably been murdered.
A second inquest in 2010 also heard that after Mr Jones was killed his body may have been burned in slaughter yards in the outback town of Hughenden.
But the coroner was forced to halt the inquiry part-way through when lawyers noticed the inquest was being heard under the 1958 Coroners' Act and not the updated 2003 legislation.
The family hopes a Brisbane Supreme Court judgment to be delivered on Wednesday will finally bring clarity to the issue.
"If Tony's inquest was being heard unlawfully under the wrong coroner's act it could jeopardise any future criminal prosecution of the suspects," Mr Jones' brother Mark said.
"We're not getting younger and dad is now 94 - we just want to see justice for Tony before it's too late."
Despite the possibility of further delay if the current inquest is deemed unlawful and abandoned, there could be a silver lining to the saga.
Mark Jones says a fresh inquiry under the 2003 version of the act should allow the coroner to investigate what the family believes was botched police work following Tony's disappearance.
"They've lost evidence and failed to follow up numerous leads that could have already led to answers about Tony," he said.
The Queensland coroner is set to hear two other cold case inquests under the 1958 version of the act.
An inquest into missing WWII veteran Leslie Ball, who disappeared from Townsville 26 years ago, was to commence on July 15 but was adjourned in June to consider new evidence.
No date has been set for an inquest into Sharron Phillips' disappearance from Brisbane in 1986.
Queensland police have refused to comment on Mr Jones' disappearance while the matter is the subject of an inquest.
© AAP 2019