More than 22,000 Aboriginal and Torres Strait Islander children and young people are in out-of-home care (OOHC), the latest data from the peak body for Indigenous children has said.

Speaking at the AbSec conference on the land of the Mulgoa clan of the Dharug Nation, SNAICC – National Voice for our Children chief executive, Catherine Liddle said the latest numbers showed not a failure of the system, but one working exactly as it was designed.

The child protection system is "deliberately intended to harm us," Ms Liddle said.

"Deliberately intended to remove as many children from their families as possible. It was built to remove children from their families.

"Before colonisation, we didn't need a system to protect our children….to put our children in prison."

Her comments reiterated the words of Yoorrook Justice Commissioner, Sue-Anne Hunter, who told the conference on Tuesday: "The colonial machine is working exactly as its planned".

In the new SNAICC Family Matters report, to be released next week, Ms Liddle said 22,908 First Nations children were in OOHC across the country.

"They are not statistics; they are our families, our babies," she said.

"The numbers don't tell us what that lived experience was. They don't tell us [that] the payments were cut off and there was no way to buy shoes for their children."

Addressing the conference, Ms Liddle highlighted the recent decision of the NT government to lower the age of criminal responsibility, which has been heavily criticised by legal, Indigenous, human rights and medical groups.

"We have seen one new government move to lock up our children from the age of ten," she said.

"Those elections were won with the deployment of our children; our children were weaponised."

Highlighting crime levels in the NT, which have been well documented, Ms Liddle said: "These are the children of the intervention."

Enacted in 2007 across 77 Aboriginal communities, the intervention included restrictions on alcohol and pornography, the quarantining of welfare payments through the BasicsCard and the cancelling of a community employment program.

The government introduced legislation enabling measures to suspend the application of the Racial Discrimination Act.

In August, former Prime Minister John Howard defended the measures introduced during his administration, including the intervention, calling them "totally justified".

"The intervention was totally justified because the NT government had failed in its responsibility to Indigenous children in the Territory, despite the findings of a report that that government had commissioned," Mr Howard said.

Reporting from journalist Amy McQuire revealed misinformation and false accusations which helped the government at the time gain support to enact the intervention.

Indigenous organisations have argued the long-term impacts of the intervention continue to be felt across communities in the NT, through levels of OOHC and incarceration.

"The only people being held accountable for the failures of the intervention, are the children of the intervention," Ms Liddle said.

"Closing the gap starts with our children."

She welcomed the federal government's commitment to do things differently in response to a Productivity Commission report which found governments had largely not fulfilled their commitments in relation to Closing the Gap.

"To that, I say 'hear! hear!'" Ms Liddle said. "But I acknowledge many of you have heard words like that before."

"Let's redesign; let's start again.

"Make sure Aboriginal and Torres Strait Islander people lead that design and reform."