Josh Warneke, 21, died from severe head injuries in the early hours of February 26, 2010, after a night out with mates in Broome, in Western Australia's Kimberley region.
Initial thoughts were that he could have been a victim of a hit-and-run involving a motor vehicle or been assaulted and left there.Â
A criminal investigation was plagued by problems, but police thought they cracked the case in 2012, charging a man with murder.
He was sentenced to seven-and-a-half years' imprisonment for manslaughter but was later acquitted, with a police review finding insufficient evidence.
Gene Gibson, a cognitively-impaired Aboriginal man from a remote desert community who spoke little English and was unable to understand the legal process, was wrongly convicted of causing his death and spent almost five years in jail.
He pleaded guilty to manslaughter after a series of flawed police interviews was deemed inadmissible, leading prosecutors to drop a murder charge.
Mr Gibson walked free in 2017 after appealing the conviction and was paid $1.5 million in compensation by the state government.
More than 16 years after the death, Coroner Rosalinda Fogliani has ruled Mr Warneke was likely the victim of murder or manslaughter and his fatal head injury was a result of blunt-force trauma with a weapon.
"I am of the belief that an indictable offence has been committed," Ms Fogliani said in her findings published on Monday.
"Josh's death being the result of an unlawful homicide."
Mr Warneke suffered severe blows to the back of his head with a sharp implement, resulting in a massive skull fracture that left him lying in a pool of blood.
The coroner rejected a theory the injuries might have been caused by a motor vehicle, saying there was no evidence to back the finding, such as gravel injuries or drag marks.
Ms Fogliani has reported the matter to the Director of Public Prosecutions.
Adverse findings were made against the WA police, including that the force did not have systems to investigate complex crimes regionally.
A forensics team was also not called out to the scene, resulting in samples not being obtained and the potential contamination of evidence.
The coroner also found there were failures in relation to the police interviews with the man initially accused of murder over Mr Warneke's death.
Ms Fogliani made four recommendations, including guidance on the preservation of forensic evidence in regional and remote areas.
