Detectives have launched a murder investigation after the decomposing body of a missing Sydney man was found in NSW bushland.
Hongli Qi's body was discovered by council workers in the Hawkesbury suburb of Blaxlands Ridge on August 16.
Mr Qi was last seen by his family at Town Hall Station about 1pm on May 11.
CCTV footage showed the Sydney local leaving his apartment complex on Macquarie Street later that evening.
Detective Superintendent Danny Doherty said Mr Qi's body was found "50 metres off the road in a dense bushland area".
"Obviously, his body was placed there hoping that no one would ever find it," Detective Superintendent Doherty said.
Detective Superintendent Doherty said the state of decomposition of Mr Qi's body made it difficult to determine how he died.
"The initial post-mortem hasn't been able to determine the cause of death," he said.
"But because of the circumstances of how we have found him and the circumstances of how he disappeared, we're treating it as a homicide investigation."
Mr Qi had been living with his family in south-west Sydney before moving to the apartment complex on Macquarie Street.
Detective Superintendent Doherty said the 28-year-old was known to police.
"He did have a criminal history for drug supply," he said.
"So some of the lines of inquiry, which are obvious for investigators, are his associates and connections in the drug supply network."
Homicide detectives are urging anyone who saw or spoke to Mr Qi in the weeks or days before his disappearance to contact police.
Mr Qi's body was found wearing the same dark hooded jacket he was wearing in the CCTV footage from May 11.
"His disappearance was completely out of character. His body was found some 80 kilometres from where he was last seen," Detective Superintendent Doherty said.
"We're trying to track down his movements and who we might have been with and what happened to him.
"It's really important that we get that information for his family … they're devastated about this loss."