An Adelaide man murdered because of his links to the drug trade was "walked into the scrub" in South Australia's mid-north before being killed, police have revealed.
Officers involved in the investigation into the death of Robert Atkins began a lengthy and detailed search of a 10 square kilometre area between Orroroo and Peterborough on Tuesday in a bid to find his remains.
The 29-year-old is one of three men thought to have been killed by the same group, described previously as low-level drug dealers and petty criminals.
Detective Superintendent Des Bray said the search would start in priority areas and then be expanded in the coming days and weeks.
"It's hot, it's windy, it's dusty but we'll do anything we can to find Robert," he told reporters.
"I'm as confident as you can be. We've committed a lot of resources to find him and we wouldn't commit the resources if we didn't think there was a good chance.
"We need to do and we will do everything humanly possible to find Robert."
A number of wells and ruins have been searched in the area before, but this is the first extensive operation. Mr Atkins went missing in about November 2020 and was thought to have been held and tortured for up to a week before being forced to commit crimes for his captors.
Supt Bray said it was difficult to know the exact circumstances under which he was brought to the area where he was killed.
"But we do know that in his final moments that he was walked into the scrub, most likely against his will," he said.
"That's where he was murdered."Â
Late last year police established a special task force to look into the killing along with the deaths of Trevor King and Jeff Mundy.
Mr King, 41, was found dead at suburban West Lakes in January 2020 with police now believing his death was staged to look like a suicide. Police say in the months before his death, he was the victim of unlawful detention and serious assaults, resulting from a drug debt.
The debt was initially $1000 but increased to $10,000 and then $50,000 when he failed to pay. Mr Mundy, 36, was last seen in December 2020. His body has not been found, with police suspecting it was disposed of somewhere on SA's Fleurieu Peninsula.
Up to 15 people are believed to have been involved in the suspected murders and detectives are also checking another 200 overdose deaths since 2019 to determine if any more are suspicious.