The mother of slain Brisbane schoolgirl Tiahleigh Palmer says the justice system has let her daughter down after her foster brother was jailed for a minimum of three months.
Josh Thorburn, 21, was sentenced in the Beenleigh District Court on Thursday to 15 months' imprisonment, to be suspended after three months, for perjury and perverting the course of justice.
Thorburn admitted lying to police and the Crime and Corruption Commission (CCC) on multiple occasions during the investigation into Tiahleigh's murder in October 2015.
Joshua Thorburn arriving at Beenleigh court for sentencing on Thursday. Source: AAP
Tiahleigh's mother Cindy, who was part of a packed gallery for the sentencing, indicated she would seek to have Thorburn's sentence reviewed.
"The justice system has let us down horribly today," Ms Palmer said outside court.
"Most of all they've let down Tiahleigh and her fight for justice."
Joshua Thorburn, foster brother of slain schoolgirl Tiahleigh Palmer, has been jailed. Source: AAP
The court heard Thorburn was called to a family meeting regarding Tiahleigh after arriving home on October 29.
Fearful of his father Richard and what he might do, Thorburn lied to police on two occasions about seeing Tiahleigh the morning after police allege she was murdered.
During a CCC hearing into the alleged crime in June 2016, Thorburn again claimed to have seen Tiahleigh on October 30, 2015 and denied knowing about any sexual activity she was involved in or who had killed her.
Judge Craig Chowdhury said while he accepted Thorburn had an "acute fear" of his father and was being pressured by his parents to lie, he had time and opportunity to tell the truth.
"A significant police investigation was substantially obstructed," Judge Chowdhury said.
Thorburn's father Richard has been charged with Tiahleigh's murder while his younger brother Trent is facing charges of incest, perjury and attempting to pervert the course of justice.
Thorburn's mother Julene was expected to face sentencing on Thursday on perjury and attempting to pervert the course of justice charges but her matter has been adjourned after she changed lawyers.