Three murders believed to be linked to the drug trade in Adelaide's southern suburbs will be the focus of a new police task force, with up to 15 people suspected of being involved in the killings.
Detective Superintendent Des Bray said 42 officers under Task Force Southern will investigate the deaths of Robert Atkins, Trevor King and Jeff Mundy.
Supt Bray said between 12 and 15 people, who he described as "thugs and bullies", were thought to be involved with the deaths related to the methamphetamine scene.
"It is alleged the men have all been murdered by low-level drug dealers and petty criminals, who get together with others to bully, threaten and stand over others," he said.
"We're not talking about gangs, we're not talking about organised crime. We're talking about low- to mid-level drug dealers."
Supt Bray said the investigation was expected to be long and challenging as he urged anyone with information to come forward.
He said anyone who provided information could be kept safe.
"The victims made bad choices to use drugs and ultimately that's led to them losing their lives," he said.
"But none of them deserved what happened to them."
Mr Atkins, 31, was held captive and tortured for up to a week before being forced to commit crimes for his captors.
Detectives believe he was murdered near Port Pirie, in the state's mid-north, with his body left near Orroroo although it has still not been found.
Mr King, 41, was found dead at suburban West Lakes in January last year with police now believing his death was staged to look like a suicide.
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 last year. His body has not been found, with police suspecting it was disposed of somewhere on SA's Fleurieu Peninsula.
Supt Bray said the task force, one of the largest assembled in SA, would also look into other drug-related deaths, including some thought to have been the result of overdoses.
"We've got three people who were murdered. We are looking at the possibility there may be other deaths," he said.
Australian Associated Press