Tiahleigh Palmer's foster brother Trent Thorburn wants to be released on bail as he appeals his four-year sentence for incest and perjury relating to his dead foster sister.
The 20-year-old has lodged an appeal against what he calls a "manifestly excessive" sentence after he pleaded guilty to having a sexual encounter with the 12-year-old in the days before her death in October 2015.
A court heard the sexual relationship between Tiahleigh and Thorburn, then 18, was the catalyst for her tragic death.
Police allege Thorburn’s father, and Tiahleigh’s foster dad, Richard Thorburn murdered her six days before they found her body on the northern Gold Coast river in November 2015.
Crown prosecutor David Nardone said it was when Thorburn feared the schoolgirl was pregnant that he confessed to his mother Julene that he’d had sex with her.
"His confession to his mother was the catalyst for Tiahleigh's murder," Mr Nardone said.
The confession to his mother came after Thorburn admitted his sexual relationship with Tiahleigh over Facebook messenger to his cousin, the court heard.
However, following her death, Thorburn repeatedly denied having any sexual relationship with his foster sister to the police as well as denying knowing anything about the murder.
He maintained he had not had sex with her at a Crime and Corruption Commission (CCC) hearing in June 2016 and it wasn’t until his CCC hearing in September that he admitted to their sexual relationship.
During that hearing, Thorburn alleged Tiahleigh had been the one to initiate sex and he had been too drunk to reject her advances – a claim Judge Craig Chowdhury dismissed as "completely implausible".
Thorburn was bashed twice in prison by fellow inmates who were jeered on by a crowd taunting “pretty boy” and “kill him”.
His bail application is set down to be heard in the Brisbane Supreme Court on Friday.