New data has prompted the head of an Indigenous justice service to accuse the Tasmanian Government of failing Aboriginal people.

Tasmanian Aboriginal Legal Service CEO, Jake Smith, said new adult prison data shows a 34 per cent increase in Tasmania's Aboriginal prison population, compared to a two per cent decline for non-Aboriginal people over the same period last year.

"This week's release of data demonstrates the Tasmanian Government is failing Aboriginal people in Tasmania," Mr Smith said.

"Let's be clear, this is not an Aboriginal people issue — this is a Tasmanian Government issue."

Mr Smith criticised lack of action from the government, which is a signatory to the National Agreement on Closing the Gap.

Target 10 of the agreement commits governments to reducing the significant overrepresentation of Aboriginal people in the criminal justice system.

"The Tasmanian Government needs to step up and follow through on its commitments under the National Agreement on Closing the Gap," Mr Smith said.

"There is so much the Tasmanian Government could be doing, but is not, to support Aboriginal people in contact with the legal and justice system."

Tasmania, similar to other states and territories, incarcerates Aboriginal people at a disproportionately high rate compared to the non-Aboriginal population.

According to the government as of 21 April, there were 871 people incarcerated in Tasmania, with 279 — or 32.03 per cent — of prisoners being Aboriginal or Torres Strait Islander.

Since the October 2020 - March 2021 reporting period both the number of Aboriginal people incarcerated in Tasmania, and proportion of Aboriginal prisoners compared to non-Aboriginal prisoners has gradually increased.

According to the Tasmanian Department of Justice in October 2020 - March 2021 there were 157 Aboriginal prisoners, or 23.7 per cent of the state's total prison population.

In the same reporting period five years later, there were 250 Aboriginal prisoners out of a total prisoner population of 844, or 29.7 per cent.

Tasmanian Minister for Justice, Guy Barnett, did not respond to questions from National Indigenous Times, however a government spokesperson — pointing to "record investments" in the Tasmanian legal assistance sector — said the state government "remains committed to improving access to justice for all Tasmanians".

"In 2023, our Government released the Changing Lives, Creating Futures Strategic Plan which continues our strong focus on rehabilitation and reintegration," the spokesperson said.

"Closing the Gap and reducing the number of Aboriginal and Torres Strait Islander people in the corrections system is one of the Strategy's key priorities, with Tasmania performing better than the national in almost all targets."

Mr Smith said the Tasmanian Government needs to prioritise funding to the legal and the justice system for Aboriginal people and not rely on the Commonwealth to do all the heavy lifting.

"However, looking at our State and across the country, it is clear much, much more also needs to be done.