An Adelaide man missing and thought murdered may have been held for up to a week and assaulted before his death, police have revealed.
Robert Atkins was involved in the local street-level drug scene and Detective Inspector Brett Featherby says it's that involvement that police believe led to his killing.
He was reported missing by his mother in January but checks have found no activity on his phone or through his bank accounts since mid-November last year.
On Thursday night, a search was conducted at a home at Christie Downs, with sections of flooring removed for further forensic testing.
"It's evident that when a person is held against their, especially for a period of four to seven days and assaulted and their body is disposed of, we know there are more than one or two persons involved in the murder," Det Insp Featherby said.
"If there is someone that's been involved in Robert's death, even if it is only a small part, we ask that they come forward and speak to police before we come and speak to them."
Det Insp Featherby said detectives were following several lines of inquiry and believed there were people who had knowledge of Mr Atkins' background and his subsequent murder.
He said police believed the 29-year-old had debts as a result of his involvement with drugs but those debts were not significant.
The disappearance of Mr Atkins and his likely murder has been declared a major crime.
