Governments are refusing scrutiny of their prisons because they know "human rights abuses are happening regularly inside these horror houses", says federal Senator Lidia Thorpe.

On Monday, National Indigenous Times reported UN Special Rapporteur on the rights of Indigenous Peoples, Albert K. Barum, said his visit to Australia would no longer include visits to facilities in Townsville or Darwin, or meetings with officials in the NT and Queensland.

It marks the second time in less than 12 months that the Northern Territory Government has blocked a UN delegation from inspecting detention facilities.

Both the NT and Queensland have been criticised for legislation — including stricter bail laws — that experts say is contributing to an increase in the number of children behind bars. Queensland locks up more Aboriginal children and young people than any other jurisdiction, while virtually all children in prison in the Territory are Aboriginal.

In response, Senator Thorpe said the "public would be disgusted to see the harms that their taxpayer dollars are contributing to" in prisons across the country.

Calling for scrutiny, she told National Indigenous Times: "We know what happens in these places."

"People are locked in prolonged torture-like isolation; there are major problems with overcrowding, inadequate sanitation and healthcare, children are subjected to violence and sexual abuse by prison guards, and women are being shackled while giving birth."

Last month, two private members' bills introduced by Senator Thorpe — aimed at stopping the shackling of pregnant women and the strip-searching of children — failed to gain the support of the government and the opposition.

The Gunnai, Gunditjmara and Djab Wurrung Senator argued that the decision to block the Special Rapporteur was a failure of the Prime Minister and the Federal Attorney-General.

They both have "clear power to establish enforceable minimum standards across the criminal legal system, to pull states and territories into line," she said.

"The Federal Government is happy to sign up to international human rights commitments but refuses to actually act on them. It is time they set minimum standards and hold governments accountable for the treatment of people in prisons, including children."

In a statement, the newly appointed National Commissioner for Aboriginal and Torres Strait Islander Children and Young People, Sue-Anne Hunter, said the refusal to allow access to the prisons "raises serious questions about transparency and accountability".

"If governments are confident children are safe, and their rights are being upheld, independent scrutiny should not be feared," she said.

Commissioner Hunter, a Wurundjeri and Ngurai Illum Wurrung woman, said the refusal showed her that the two governments are "not treating the rights of Aboriginal and Torres Strait Islander children and young people as a priority".

"While youth detention is administered by states and territories, Australia's obligations under international human rights law ultimately sit with the Commonwealth," she said. "First Nations children should not miss out on independent scrutiny because governments dispute responsibility."

A spokesperson for Commonwealth Attorney-General Michelle Rowland said the NT and Queensland's decision not to meet with Mr Barum was a "matter for their governments".

"The decision does not reflect the position of the Albanese Government, and we encourage all jurisdictions to engage constructively with the Special Rapporteur," they told National Indigenous Times.

"The Government continues to work with states and territories to support the implementation of Australia's international obligations within their respective jurisdictions."

A Territory Department of Corrections spokesperson told this masthead the NT Government is "not facilitating a visit to the Holtze Youth Detention Centre as part of the United Nations Special Rapporteur's visit".

"Northern Territory detention facilities are subject to established independent oversight and accountability arrangements," the spokesperson said.