Police are investigating the death of a man whose body was found stuffed inside a wheelie bin on Brisbane's southside.

Officers made the grim discovery at a Yeronga Street unit complex at Yeronga around 7:00pm on Saturday.

Police said they were called to investigate after neighbours complained of a bad smell in the area.

It is believed the body had been inside the bin for up to 10 days.

Police have declared a crime scene at the house and multiple other locations as detectives work to determine the cause of death.

Police have identified the man, but would not release any information about him other than to say he was not a resident of the Yeronga Street unit.

Police want to speak to these four people, who have been in the area. ( Supplied: Queensland Police )

Joel Rivett, who was staying with a friend who lives at the unit complex, came across the body in the bin after the smell started to come into his friend's apartment.

"Just a terrible smell for a couple of days, and I went over to the bin where my mate found it, obviously just a suspicious thing going on," he said.

"So I lifted the bin and there was a couple of black bags in there. So it didn't smell too right, so we called the real estate [agent] and this is what's happened now.

"I've worked out in the bush before and smelt dead roos in the sun, and couldn't even compare to that. I'd rather stick my nose in the carcass, than that."

The investigation into Mr Mitchell's killing is still underway. ( ABC News: Julie Hornsey )

Detective Inspector Mark Thompson said police are looking to speak to four people in relation to the death.

"I believe the people that we are looking for are two males in their 30s and two females in their 20s. They have frequented this area over the last month or two, and certainly quite heavily in the last seven to 10 days," he said.

"If any members of the public know the identities or the locations of these people I ask them not to approach these four persons but to contact police."

Officers will continue to search an area between the unit and the Yeronga train station for evidence.