States and territories across Australia are bringing in punitive policies for young children "over evidence-based reform," a Parliamentary inquiry has heard.

Appearing at a Senate hearing examining Australia's youth justice and incarceration system, the lead convener of the Coalition of Peaks, Pat Turner, said a prevalence of populist policies at the behest of Indigenous children's safety was an ongoing concern.

She added this had only been exacerbated during the elections in the NT and Queensland.

"We continue to see 'tough on crime' politics play out across the country," Ms Turner said. "These approaches are completely at odds with the evidence."

She said some jurisdictions ran electoral campaigns which gave "credence to bringing in 'tough on crime' [responses] and highlighting the extent of Aboriginal and Torres Strait Islander kids, and adults, as the villains".

"There is very little we can do about that, given our population and our resources," Ms Turner said.

In Queensland, laws introduced - ostensibly titled 'adult crime, adult time' - means children as young as 10 can be sentenced to life in prison, whilst the number of children being housed in adult watch houses has continued to rise, despite outrage from a significant number of organisations.

Furthermore, in custody, children are not being given a chance to rehabilitate, the inquiry was told, instead being confronted with violence and a lack of care.

Speaking at the hearing, the interim National Commissioner for Aboriginal and Torres Strait Islander Children and Young People, Lil Gordon, said the status of incarceration for Indigenous children, "is hard to fathom, but heartbreakingly true".

She said her role - the first national commissioner for Indigenous children - was to look at organisations like the Coalition of Peaks and SNAICC and bring together the work they had already achieved.

"How do we elevate these aspirations…how are we celebrating our young people," she said.

The hearing has focussed on the ability or powers of the Commonwealth to enact the states to act on youth justice in line with the closing the gap agreement, including the reduction of Indigenous children in the criminal justice system.

Despite expressing concern around laws introduced across the country - specifically by Minister for Indigenous Australians, Malarndirri McCarthy - the federal government has failed to prevent numerous "breaches" of human rights for children—including the death of two children in WA's youth detention.

"We urge the Commonwealth to use these powers…to drive change in line with the [closing the gap] agreement," Ms Turner said.

In their submission to the inquiry, the attorney-general's Department said: The Australian Government has limited areas of responsibility for youth justice, including through Commonwealth criminal laws that apply to young people and working with states and territories to implement Australia's international obligations."

Leading Indigenous barrister, Tony McAvoy SC, told the inquiry jurisdictions across the country "appear to be openly abandoning our country's international human rights obligation".

"Unless there is some commonwealth action, this will continue to be the case. It is not a question of if the commonwealth should act, but what it should do."

"The commonwealth could legislate; the commonwealth could develop policy; the commonwealth could direct funding towards activities which promote and facilitate observation of Australia's international human rights obligations.

"There are many things the Commonwealth could do, and I don't think there needs to be a lengthy delay."

Mr McAvoy said he believed unless there was some Commonwealth intervention in youth justice systems across the country," nothing will change".

He said the Don Dale Royal Commission, of which he was heavily involved in, saw recommendations aimed at the Commonwealth, along with the Northern Territory.

The facility will house adults under a new announcement by the CLP government in the Northern Territory.

"Discussing the recent regression with my colleagues," Mr McAvoy said, "we wonder if there is going to be any change that makes a difference or are we consigning a generation of young Aboriginal and Torres Strait islander children to a life in the criminal justice system."

"Fear sells newspapers, and Aboriginal and Torres Strait islander people are the fodder for that."

Ms Turner said the Coalition of Peaks had worked constructively with the current Labor government and was reserved in her criticism. Of the Coalition, however, she noted: "We have an opposition in Peter Dutton and the Nationals who don't even want to stand in front of the aboriginal flag."

"We despair over this, and it is very difficult for us when we try to work on the basis of facts and evidence and impartiality with anybody who is in power," Ms Turner said.

"We expect this [the agreement] to be honoured no matter who wins government."