A damning internal report by the NSW Department of Family and Community Services (FACS) has found it misused its power when it placed a toddler in temporary foster care, where he drowned in an unauthorised backyard pool in 2014.
The ABC obtained the document at an inquest into the death of 22-month-old Braxton Slager.
The report also identified systemic failings which meant the boy did not receive quality care "in any environment he lived in — firstly with his mother, then with his father and lastly with his foster family".
It highlighted significant problems in the department's handling of similar cases in western Sydney, which has much higher rates of matters being closed "due to competing priorities" than the rest of New South Wales, leaving children who require care "without allocation".
The 69-page Joint Child Death Review includes a report from the company Life Without Barriers (LWB), which is contracted to manage the foster care process for the department.
It says "the death of a child in custody is the most confronting of situations" and the "distressing and deeply troubling" case shows the system did not provide Braxton "quality care, let alone adequate supervision".
The inquest heard the child's parents struggled with serious drug issues at various times.
But the decision to place him in a temporary care arrangement (TCA) was made without the informed consent of his parents, Johnny Slager and Vanessa Naumovska.
"The opinion of this review is that, however well intentioned, this was a misuse of FACS power," the report says.
Wrong to assume mother unfit to care for Braxton
It said the child's mother never gave her consent, and the father only agreed because "the caseworkers had indicated that if he did not agree then other more intrusive action would be initiated [such as Braxton being assumed into care and /or the commencement of care proceedings in the Children's Court]".
On the last occasion Mr Slager saw his son, the report said he "told Braxton that he loved him and said goodbye", believing he would see him again in a matter of weeks.
The review found it was wrong to assume the boy's mother was unfit to care for him, as she was already the primary carer for other children and "this view seems to be based on child-protection history rather than any assessment of her current parenting ability".
"Ms Naumovska clearly articulated her willingness to care for Braxton and there is no evidence to suggest that she consented to his entry into the out-of-home care system," the report says.
"Braxton's death occurred in an arrangement that neither parent willingly provided informed consent about.
"When Braxton came into foster care he was not placed with a family that provided him quality care.
"The placement was overcrowded, there were concerns about the carer's ability to cope and LWB did not provide an effective system for monitoring and support."
Reports often not responded to in western Sydney
Disturbingly, the report said this was not an isolated example.
"Many community services in the western Sydney area service a demographic with large numbers of families that are disadvantaged creating an immensely high volume of work.
"Frequently reports cannot be responded to due to resource limitations and competing priorities."
It said it is difficult to find out-of-home care for children in emergency situations and that "this context reflects the reality for many large statutory systems and many FACS community service centres".
The report recommends a review be conducted to determine how best to resolve resourcing issues that impact on the allocation of risk reports.
Braxton and his siblings were reported to authorities four times between July 2012 and June 2013.
"It is likely, due to local factors such as staffing levels, only matters receiving less than 24 hours response were able to be allocated," the report says.
Braxton's case recommended a response within 72 hours, and "given the nature and number of reports received during this time it is unlikely that reports about Braxton would have been allocated".
It also recommends ensuring that "foster carers are required to provide a certificate of compliance in relation to swimming pools and spas prior to authorisation".
Caseworkers cut, budget stripped, Opposition says
The report also reveals the level of demand being placed on FACS offices in western Sydney in the lead-up to Braxton being placed in foster care.
It shows in July 2012, the St Mary's office closed 60 per cent of "risk of serious harm" reports without assessment due to competing priorities, while in June 2013 at Mt Druitt 86 per cent of reports were closed without assessment.
New South Wales Opposition's Family and Community Services spokeswoman Tania Mihailuk said during that time the State Government was cutting millions of dollars from the FACS budget.
"Significant caseworker cuts, children being reported as at risk of harm and then without any assessment these cases were closed because of competing priorities," Ms Mihailuk said.
"This is a report the Government has tried desperately to cover up.
"There's a constant veil of secrecy from this government when it comes to child protection."
The ABC has sought comment from Family and Community Services Minister Pru Goward.
Legal stoush to keep documents private
FACS sought public interest immunity, which would prevent media coverage of this report.
Barrister Mark Lynch told the court that, as in the case of the police debriefing after the Lindt Cafe siege, there were elements to this report that were not suitable for publication, and may deter workers from being candid in future case reviews.
Mr Lynch said their cooperation was crucial to ensure "tragedies such as this don't occur".
The barrister representing the child's parents, Jerry Prus-Butwilowicz, argued that "public interest is best served by agencies who quite often work in shrouds of secrecy not being able to do so".
Mr Prus-Butwilowicz said the documents "really go to there being serious, systemic problems".
The ABC opposed this request, arguing it was in the public interest to release the information and Deputy State Coroner Harriet Grahame agreed.
"In my view there is great benefit in not having half the story," Msh Grahame said, adding that there is enormous public interest in investigating the cause of death of a vulnerable child in foster care.
Ms Grahame said the goal was not to apportion blame, but to uncover what happened, and that the FACS documents are "more than merely relevant".
The inquest continues.