Qld inquest into Tialeigh's final moments

It's been almost six years since three fishermen made a horrific find on the banks of the Pimpama River - the body of murdered schoolgirl Tialeigh Palmer.

The 12-year-old girl was naked except for a pair of underpants when her body was found on November 5, 2015.

Her tiny body was so badly decomposed, authorities have never been able to determine how she died.

Deputy State Coroner Jane Bentley is hoping to finally give Tialeigh's family answers during a two-day inquest starting on June 8.

The schoolgirl's foster father, Rick Thorburn, is serving a life sentence for murdering Tiahleigh on October 29, 2015.

In the hours before, Tialeigh had been to a hip-hop dance class where she complained of stomach pains, counsel assisting Kate McMahon told a pre-inquest hearing on Tuesday.

That same night, Thorburn's son Trent confessed to mother Julene that he'd had sex with the schoolgirl and feared the stomach pains were a sign she was pregnant.

Thornburn and his wife feared a pregnancy could mean Trent would go to jail, the court was told.

That night, the family - Julene, Trent and brother Joshua went out, leaving Tialeigh home alone with Rick Thorburn.

She was never seen alive again.

When the family returned, Thorburn simply told them: "Tialeigh is no longer with us. I hope you know what that means."

Thorburn bluntly said he had "taken care of it" before warning them not to ask questions.

"There was then a period of about two hours where Mr Thorburn and Tialeigh Palmer were alone in the house together, between 8pm and 10pm," Ms McMahon said.

"During that two-hour period he killed Tialeigh Palmer."

Every member of the Thorburn family was convicted of being part of the crime - Rick Thorburn for the murder itself, Trent for incest, and wife Julene and his other son Joshua for being part of an elaborate cover-up.

Thorburn was sentenced to 20 years in jail.

Tiahleigh's murder spawned two major reviews and resulted in stronger criminal checks for people seeking to become foster carers or wanting Blue Cards to authorise them to work with children.

Despite internal reviews and criminal trials, no one knows what happened to Tialeigh Palmer in her final moments.

"(Thorburn) has pleaded guilty to her murder but has never given an account, either on oath or otherwise, as to how he killed her," Ms McMahon said.

"One of the primary focuses of this inquest will be to see if anything more can be learned about that two-hour period of time.

"What actions Rick Thorburn took when he killed Tialeigh Palmer and how Tialeigh spent her last hours and moments."

The Thorburn family will be called as witnesses and compelled to give evidence to the inquest.

"The people who loved Tialeigh want answers about what happened to her in her last hours and moments and how Richard Thorburn disposed of her body."