Two people were caught on camera acting suspiciously in the area where the dismembered remains of an Adelaide man were found in a wheelie bin, police have revealed.
In the continuing investigation into the brutal murder of Geoffrey McLean, police say CCTV footage from a nearby industrial premises shows two people wearing headlamps or carrying torches.
The footage was captured near the paddock at suburban Salisbury South where Mr McLean's remains were found in October last year.
It was taken before dawn on August 24, five days before the 55-year-old was reported missing.
Detective Inspector Brett Featherby said it was not known if the two people were involved in the disposal of the bin containing Mr McLean's remains.
"They are acting suspiciously and we believe they enter directly into the area where his remains were located," Insp Featherby said.
"We'd like to identify those persons and identify what their role is in Geoffrey's murder."
Investigations have confirmed there were attempts to bury Mr McLean in the paddock but those responsible gave up because the ground was too hard or because they were disturbed.
Police found two shovels, a post hole digger and a garden fork nearby.
Insp Featherby said while the investigation into Mr McLean's death was progressing well, police had still not found his head or limbs.
They have urged a previous caller to Crime Stoppers who provided "accurate and credible" information to contact them again.
"The information that was provided was not only related to the murder but also to previous violent assaults on Mr McLean," Insp Featherby said.
"We believe the information, if we can speak to that caller further, will go a long way to solving the murder. That person can still remain anonymous."
Insp Featherby said detectives believed they knew the motive for Mr McLean's killing but said only that it was not drug related.
Police previously detailed that he had been subject to four violent attacks in the months before his disappearance.
On April 10 he was attacked by a person with acid and three days later was struck with a log splitter and received serious head injuries.
On May 9 his car was set on fire at his home and on May 10 he had a bucket of acid thrown over him, causing serious burns to his upper back and shoulders.
