The man was last seen in the water by friends before disappearing a short time later.
The contaminated soil was put down to the region's historical industrial use as a tar processing plant.
Thousands of commuters have been warned to make alternative travel arrangements.
Police have been unable to find out what caused the"big splash"in the Brisbane River last month.
Behind the scene,scientists have new techniques of preventing increasing quantities of sediment containing nitrogen and phosphorus flowing down the Brisbane River. If successful they could have a major impact. But they need political support.
More than a thousand people have died in Australian rivers since 2008.
As the Brisbane River develops its tourism reputation,attention is turning to the pristine Moreton Bay Islands.
If planners could start from scratch,Brisbane would have a system of underwater tunnels and a riverfront skyline similar to New York.
The river is a central part of all Brisbanite's identities,whether it's which side of the river we call home,or what it represents to us culturally.
How some people (and a dog) have turned the Brisbane River into a workplace,backyard or playground.
An analysis of the multibillion-dollar economic value of the Brisbane River's bustling shoreline.