Two people who were bound and locked in a toolbox which was then dumped into a lagoon south of Brisbane could be heard "calling out and pleading for their lives" as they were submerged, a court has heard.

Key points: The pair were allegedly driven to the lagoon while trapped in the toolbox

The pair were allegedly driven to the lagoon while trapped in the toolbox Prosecutors say Mr Tahiata took police to where the box had been dumped

Prosecutors say Mr Tahiata took police to where the box had been dumped He allegedly said in an interview that the pair were still "calling out" as it was placed in the water

On the first day of his Supreme Court trial, Tuhirangi-Thomas Tahiata pleaded not guilty to the murder of Iuliana Triscaru and Cory Breton in January 2016.

Their bodies were found in a large toolbox that had been submerged in a lagoon in Kingston, south of Brisbane.

The court heard Mr Tahiata was one of several people involved in their deaths.

In his opening statement, Prosecutor David Meredith told the Supreme Court Mr Breton and Ms Triscaru were lured to a unit in Kingston, where they were bound with tape and later put into a toolbox.

The Crown alleges after some hours, they and the toolbox were loaded onto a ute and driven to a lagoon by Mr Tahiata and another man.

Iuliana Triscaru and Cory Breton's bodies were found in the toolbox. ( Supplied: Queensland Police Service )

The court heard in an interview with police Mr Tahiata said the two victims were still "calling out and pleading for their lives" after the toolbox was placed in the water.

The Crown Prosecutor said Mr Tahiata admitted his involvement and took police to the lagoon to show them where the toolbox was dumped.

"At that stage when he made those confessions he was claiming that he did it on his own," Mr Meredith told the court.

"He later gave a different version which the prosecution says is the true version which was that other people were involved."

The court heard Mr Tahiata told investigators it was another man who put the toolbox into the water.

"If these facts are true and the accused and others say that they are then this is a breathtakingly evil act," Mr Meredith told the court.

The court was told Mr Breton and Ms Triscaru were both drug dealers.

Mr Tahiata's defence is yet to make its opening address.

The trial is expected to run for up to three weeks.