Seventh Logan murder accused very upset

A seventh Logan person charged over the bodies-in-the-box murder case is very upset by the allegations, his lawyer says.

Tepuna Tupuna Mariri briefly fronted the Brisbane Magistrates Court on Wednesday and was remanded in custody to reappear in court on March 21.

Mariri, 25, is among six men and one woman accused of murdering Cory Breton, 28, and Iuliana Triscaru, 31, last month.

Forensic officers are yet to confirm, but police are convinced it is the bodies of the pair who were found in a large metal toolbox submerged in a Logan dam, south of Brisbane, on February 11.

They had been missing since January 24.

Outside court, Mariri's lawyer John Ide said his client was shattered by the allegations and would be defending the charges.

"He's pretty upset as you could see when he was in the dock," Mr Ide said.

Police believe the murders were drug related.

They allege Mr Breton and Ms Triscaru were beaten at Mariri's Kingston unit in a dispute over a drug debt before being bound and stuffed in the two-metre long box.

The pair were then allegedly driven to the dam off dead-end Mudgee Street where they were both shot in the head and the box thrown into the water.

Holes were reportedly drilled in the box to help it sink.

Mariri joins Davy Malu Junior Taiao, 21, Stou Daniels, 21, Trent Michael Thrupp, 22, Webbstar Latu, 31, Tuhirangi-Thomas Tahiata, 24, and mother-of-seven Nga Tokoona Maretti, 36, who are all in custody facing two counts of murder.