Detectives are investigating why two men were arguing on the banks of a river south of Brisbane shortly before one was pulled dead from the water.
Police say the two men knew each other and got into an "altercation" at the Logan River early on Friday.
At 7am, a male caller phoned police to report a missing man.
The body of a 27-year-old male was recovered half an hour later by a swift water search team.
Logan District Detective Acting Inspector Nicola Brown was asked about reports the men had been play wrestling before the body was found.
"I can confirm there was an altercation involving two males, known to each other, on the banks of the river and that's the subject of our investigation," she replied.
The other man is in custody and assisting the police investigation, which will look at whether the dead man was pushed into the water.
Officers are also working to establish how long the man was in the water before his body was found.
"Police were called just before 7am, he was recovered at 7.30am. At this point in time it's unknown how long he was in the river, but it may have been up to an hour or two before that."
Police have informed relatives of the man's death. He and the man in custody are both from Eagleby.
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