South Australian Police have declared a major crime after a bushwalker discovered a “very decomposed” body in scrub south of Adelaide, with detectives probing whether the person was murdered.

The remains were found about 5.30pm on Friday, roughly five to six metres down an embankment off a track near Mount Alma Road at Inman Valley on the Fleurieu Peninsula, according to police.

“The remains are very decomposed, they have likely been in this location for several years,” Detective Inspector Andrew Macrae told reporters on Saturday.

“The circumstances in which we found it make us very confident that the person was unfortunately murdered.”

Police believe the victim died years ago before being left at the site.

Forensic testing is now underway to try to identify the person, with Macrae expecting early results within days.

“I’m confident it won’t take too long… but we have to go through a process to make sure we get it right,” Macrae said.

One line of inquiry will examine whether the case has any connection to Taskforce Southern, which is investigating the alleged drug‑related murders of Trevor King, Robert Atkins and Jeff Mundy in Adelaide’s southern suburbs.

Mundy was last seen in 2020 at Seaford, about 40km from Inman Valley where the decomposed body was found.

“Just because of the geography, it’s one of the considerations we will be looking at,” Macrae said.

Mundy’s unsolved death has been declared a major crime and is one of three linked to gang of drug dealers.

It’s believed all three deaths were over a drug debt.

In 2022, police believed Mundy was being held captive before his death and there are numerous people involved.

“We still believe his remains are on the Fleurieu Peninsula,” Major Crime Investigation Branch Detective Inspector Brett Featherby said at the time.

“We believe that not only are a number of people involved in Jeff’s murder, but also in the disposal of his body.”

“Major crime is also exploring the involvement of members of drug syndicates in the Lonsdale area, Aldinga, And Sellicks beach and their role in Mundy’s murder and disappearance.“

The remains of Atkins were found in 2023, in a well at an abandoned rural property in the state’s Mid North.

King was found dead in waters off West Lakes in January 2020.

Major Crime detectives, local patrols and forensic officers have spent the weekend at the scene.

No charges have been laid against anyone for the murder of Jeff Mundy.