Tiahleigh Palmer's Foster Father Has Been Arrested Over Her Murder

A 56-year-old man, reported to be the foster father of murdered Queensland schoolgirl Tiahleigh Palmer, has been arrested over her death. Rick Thorburn was charged with murder Tuesday morning by Queensland Police—his wife, Julene, was also taken into custody.

The pair were accompanied by two unidentified men, aged 19 and 20, who were also taken to Logan Police Station for questioning. Police have confirmed all four suspects were known to one another.

Twelve-year-oldTiahleigh Palmer went missing on October 30, 2015 after she was dropped off at school by her foster father, Rick Thornburn. Detective Superintendent Dave Hutchinson told VICE, "We know that Tiah walked out of the school willingly at about 0820 hours."

A week later, the 12-year-old's remains were found by three fishermen in the Pimpama River on the outskirts of the Gold Coast, 30 kilometres from where she was last seen.

The arrests come after homicide detectives last week seized a blue 2009 Ford Falcon XR6, which was described as a "vehicle of interest" in Tiahleigh's murder. On Monday, Tiahleigh's biological mother, Cindy Palmer, posted about the vehicle on Facebook—saying it belonged to the 12-year-old's foster parents at the time of her death. Investigators say Mr Thornton sold the car in October last year following Tiahleigh's death.

Police asked Cindy Palmer to remove the post; however, the Courier-Mail is reporting it read: "The car that was seized is identical to the one that… they had sold within days of Tiahleigh's body being found," she wrote. "[They] were the carers of Tiahleigh, the people who were intrusted (sic) where her care and wellbeing, the same carers who are publicly selling up everything they own."

Cindy Palmer also expressed her discontent with local law enforcement whom she accused of withholding information about her daughter's murder investigation. She said she was frustrated that findings from the investigation were relayed to her from members of the community and not from police.

But the Palmer investigation was plagued with issues, many stemming from the fact that Tiahleigh was a foster child. Police were criticised for waiting six days before going public about the schoolgirl's disappearance; however, they were limited by the Child Protection Act, which prevents naming children in state care.

Rick Thorburn is due to appear in the Beenleigh Magistrates Court on Wednesday.

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For more on this case read: The Strange, Sad Case of the Australian Girl Whose Disappearance and Death Sparked National Headlines