The number of children in NSW government care when they died has risen for the third year running, with 100 children known to the state dying in 2020.
The government's latest report into child deaths reviewed each of the 100 cases known to the Department of Communities and Justice (DCJ) who died in 2020.
NSW Communities and Families Minister Alister Henskens said the report "provides a deeper understanding of how we can improve".
"The death of a child is profoundly distressing and has far-reaching implications for all those who knew and loved them," Mr Henskens says.
Risk of significant harm (ROSH) reports had been conducted in the previous three years for 72 of the children who died in 2020.
Twenty-three children were known to the department because of a ROSH report on their siblings, and five of the children were in out-of-home care.
Care for those five children, including one whose care was shared with a relative, is allocated to the Minister, although Mr Henskens only began the role in May of this year.
Babies accounted for 45 per cent of the deaths and the most common causes were illness and disease, accounting for 36 per cent of all deaths.
Sudden unexpected deaths in infancy (16 per cent) and extreme prematurity (9 per cent) were also prevalent factors.
Twelve children, aged as young as 12 to 17, took or were suspected to have taken their own life in 2020, the highest proportion since 2016.
The number of children taking their own life was also the highest number in an individual year, of the 42 cases between 2016 and 2020, during which 40 per cent of the children were Indigenous.
In 2020, 23 Indigenous children known to the department died, almost a quarter of all deaths.
The report notes those "confronting" statistics "expose the continued and devastating impact of colonisation on Aboriginal families and communities".
"They highlight the ongoing trauma and oppression Aboriginal children face, and the need for improved child protection and system responses to Aboriginal children experiencing suicidal behaviour," the report reads.
"The historic pattern of First Nations children being over represented in the system and in these statistics is one which must be addressed as a priority," Opposition Aboriginal affairs and treaty spokesman David Harris says.
In October, a NSW budget estimates hearing was told 47 per cent of the 91 children in alternative care arrangements were Indigenous.
In answers to questions on notice, the hearing was told at least $129 million - roughly 16 per cent of the $764 million spent on child protection - was "directly allocated to family preservation programs" designed to keep children with their families and away from out-of-home care arrangements.
The answer noted "supports to intervene early, preserve families together, and restore children to their birth families are included within a number of programs" and some of the work being done by caseworkers "cannot be accurately quantified in monetary amounts".
That hearing also heard of a 12-year-old Indigenous child who had spent more than 300 days living in a flat.
He was still in out-of-home care last month but had left the alternative care arrangement and was being case managed "through a contracted non-government organisation" in the Nepean Blue Mountains district.
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Australian Associated Press