THE foster brother of murdered Queensland schoolgirl Tiahleigh Palmer has reportedly become a target while in prison.

Trent Thorburn, 19, is alleged to have been involved in an incestuous sexual relationship with the 12-year-old before her death.

According to the Courier-Mail, he was set upon by prisoners at the South Brisbane Arthur Gorrie Correction and bashed in two separate incidents over the weekend.

He is believed to have received only minor injuries.

The teenager reportedly remains at risk, with inmates encouraging each other to bash him on sight, the Courier-Mail reports.

Trent Thorburn is being held on charges of incest, perjury, and perverting the course of justice.

He appeared in Beenleigh Magistrates Court last week where he was denied bail. Police claimed the dancer and trade apprentice feared he had made his foster sister pregnant days before his father allegedly murdered the schoolgirl.

Tiahleigh was last seen alive in October last year and her body was found on the banks of the Pimpama River on the Gold Coast a week later on November 6.

Her foster father Rick Thorburn has been charged with her murder and is due to face court in December. He has been imprisoned after waking from an induced coma after a suspected self harm incident following his arrest.

Rick Thorburn’s wife Julene, 54, and eldest son Josh, 20, have been charged with perjury and attempting to pervert the course of justice and have been released on bail.

Forensic officers have spent days scouring the family’s Chambers Flat property, considered the primary crime scene.

Searches of the acreage have so far failed to recover Tiahleigh’s backpack and school uniform.

Tiahleigh lived with the Thorburn family for 10 months before her disappearance and death last year.