New South Wales premier Chris Minns has defended the increasing number of Aboriginal children in custody in the state.

New data from the NSW Bureau of Crime Statistics and Research (BOSCAR) found the number of young Aboriginal people in custody in New South Wales increased almost 22 per cent in the last year as new youth bail laws have taken effect.

Appearing at budget estimates on Wednesday, the Labor premier defend his governments policy, which has seen bail laws strengthened, arguing the increased numbers meant the community was being protected.

"The prison population when we got into government was 12,400. Today it sits at 13,300 as a result of our changes to remand," Mr Minns said.

"There was 4,800 people in remand in NSW prisons. Today the number is 5,800."

One of the principal recommendations from the 1991 Royal Commission into Indigenous Deaths in Custody was Indigenous people should only be incarcerated as a last resort.

"Now the Greens don't like those statistics," Mr Minns said, "but it's important that the public know that we are prepared to make change when we see problems in our community, and I'm not done yet."

Posing the decision to house more children in custody in a political context, the Premier added: "I think the government's record when it comes to confronting violence in our communities is better than the previous government."

In December 2024, 129 Aboriginal young people were in detention—57.3 per cent of the youth detention population and an increase of 23 people (21.7 per cent) in 12 months.

"The increase in young people in custody since December 2023 is mainly due to an increased number of young people on remand," BOSCAR executive director Jackie Fitzgerald said earlier this month.

"Over the past two years there has been [a] rise in the bail refusal rate for young people, from 13.7 per cent in 2023 to 15 per cent in 2024."

The new bail laws introduced last year outraged youth and Indigenous advocates, as well as many in the NSW Labor party, and were labelled a "devastating betrayal of Aboriginal children in NSW" by Aboriginal Legal Service (ALS) NSW chief executive Karly Warner.

"Bad policy is easy to print in a tabloid, but impossible to implement safely and impossible to undo in a child's life," Ms Warner said earlier this month.

"The Premier must answer this question: is your objective to reduce crime or to improve headlines? We appeal to Premier Minns to deliver good government guided by evidence."

Set to expire in April, the government announced earlier this month they would extend the 'trial' for three more years, which is expected to be introduced into parliament this week.

In a fiery exchange at estimates on Wednesday, Greens spokesperson for justice, Sue Higginson, confronted the Mr Minns with observations from judges who have called out the bail laws as unfairly targeting children.

Last year, Justice Julia Lonergan argued it was a "concern that it [the new bail provision] operates in an unfairly discriminatory way upon a section of the community - children aged 14 to under 18 - who have been widely and specifically recognised as a group that need support and guidance, not incarceration and disconnection from their family and the community," whilst another judge argued the laws were "defying the principles of equal justice".

The Premier said he didn't accept the characterisation from the legal experts, arguing the fear of youth crime in the state gave rise to the laws' appropriateness.

"There's many stakeholders that step in and criticise government legislation and laws, even eminent ones from the bench," he said.

"But that doesn't mean that we hand over the administration of justice or law making to the Supreme Court. Parliament needs to make these decisions."

In NSW, youth incarceration costs $2,814 per child, per day, according to 2023-24 Productivity Commission data, with the state spending over $223 million to imprison children and young people.

"Locking kids up has never worked, anywhere," Ms Warner previously said.

"Yet at a time when families are struggling under the cost-of-living crisis, the NSW Government is costing taxpayers millions in with its failed bail laws and law-and-order rhetoric."