A Cairns judge has found child safety officers did not properly warn a family of teenage girls about a foster child, who sexually abused them after raping a three-year-old girl.
The teenagers, who are now women, were awarded $800,000 on Tuesday, after successfully suing the Queensland government.
Cairns District Court Judge Brian Harrison found the abuse, committed in the girls' family home north of Cairns in 2006, could have been avoided if officers from the Department of Child Safety (DOCS) had "exercised relevant care and skill".
He heard the 14-year-old offender had been charged with raping a three-year-old girl at another foster home before he was approved to stay with the teens. He was later convicted of that crime.
The women argued DOCS had neglected their duty of care and put them at unreasonable risk of psychological or psychiatric harm by not giving their family all the information they needed to make an educated decision on caring for the boy.
But lawyers for the state government claimed two of the sisters contributed to negligence by not locking their doors, or telling their mother the boy was coming into their bedrooms.
They also said the mother, who had looked after the boy numerous times since 2003, knew of the rape and that the boy enjoyed the presumption of innocence when he was placed.
The teen, who had spent most of his younger years on Cape York, went on to commit numerous acts against the sisters.
Judge Harrison heard the mother had become close to the child since first caring for him and asked the department how she could arrange to have him live in her home in 2005.
But she claims she would not have taken him in if she'd known of a number of concerning incidents, including the teen touching a female staff member at a boys' home.
"It was reasonably foreseeable to DOCS that the foster child ... did present a risk to the teenage girls," Judge Harrison said in his judgment.
"No effort appears to have been made to ensure that the third party (mother of girls) and her family were made fully aware of the risks."
Judge Harrison awarded two of the sisters more than $350,000 and one close to $100,000 for psychological injury and loss of income.
He rejected the state government's contention their mother should pay some of the damages, amid claims she had initially told the girls not to report the abuse.
The boy has previously been prosecuted for crimes committed against the sisters and three-year-old.