Police have revealed that the bodies of two people found in a dam in Queensland's South Burnett region were chained together.
The bodies of a man, identified as Darryl Smith, and a woman in her early 40s were found by a member of the public at the Gordonbrook Dam, about 250km northwest of Brisbane, on Saturday about 3.30pm.
Detective Senior Sergeant Paul McCusker says the woman hasn't been identified yet and it's still unclear how the pair died.
"A post mortem is being undertaken tomorrow, and it's not until that's undertaken, and our inquiries, that we will be in a position to state how these two people have died," he told reporters on Monday.
"What I can tell you is the two people were connected by a chain, that's correct."
The pair's bodies may have been in the dam for some days as Mr Smith's white 2004 Holden Commodore station wagon with Queensland registration 306BS3 had been parked in the nearby picnic area since March 13.
Sgt McCusker said he wasn't sure why the bodies hadn't been found earlier, but indicated they may have been weighed down before becoming dislodged and floating loose.
"There is a suggestion they may have been weighted at that time, yes," he said.
He wouldn't confirm if any note had been found on the car, but said at this stage detectives were not looking for another person involved in the pair's deaths.
"We go to these investigations very open minded as to what may have occurred at this stage," Sgt McCusker said.
Without knowing the woman's identity, he said, it was also hard to work out whether or not they were a couple.
He also refused to say if Mr Smith had been known to police before his body was found.
Sgt McCusker said it was unclear where the two had been staying, but a blow-up bed found near the car indicated they had been staying at the dam.
Police have also released the last known photo of Mr Smith alive, taken at the Wondai Post Office on March 10, and called for anyone who saw him around or after that date to contact them.
"We would love to hear from any of the public who may have seen the van or seen Mr. Smith or a female he may have been travelling with at the time in the Kingaroy area," Sgt McCusker said.