A Sydney former gym manager likely met with foul play before a council worker stumbled across his decomposing body 80 kilometres from where he was last seen.
Hongli Qi, 28, was last seen leaving his apartment complex in Sydney's CBD about 6pm on May 11, having earlier seen his family near Town Hall.
Two months passed before a council worker in Blaxlands Ridge, northwest of Sydney, found a decomposing body on August 16.
A post-mortem identified the body as Mr Qi's.
"He was found about 50 metres off the road in dense bushland ... by chance, by a council worker," homicide squad commander Detective Superintendent Danny Doherty told reporters on Tuesday.
"Obviously, his body was placed there (by someone) hoping no one would ever find it."
Mr Qi was known to police, having driven through a random breath test site and then throwing a garbage bag containing two kilograms of meth out the window.
He pleaded guilty to drug supply and finished serving a three-year sentence in February.
Det Supt Doherty said a line of inquiry was Mr Qi's associates and connections in the drug supply network.
The initial post-mortem examination was unable to determine a cause of death while police currently have no timeline on when Mr Qi was killed due to his body being exposed to the elements for potentially months.
"It's quite a complex investigation and there are two months where we have to close that timeline," he said.
He wasn't known to be working at the time of his disappearance but had previously worked as a gym manager, pest controller and in sales, court documents show.
He'd also struggled with cocaine abuse, binge drinking and gambling - compounding financial problems and his depression.