A report released today shows greater investment in drug and alcohol treatment and a shift away from imprisonment could help cut crime among Indigenous offenders.

The report was penned by Deloitte Access Economics at the request of the National Indigenous Drug and Alcohol Committee.

It recommends diversionary programs to non-violent repeat offenders who are Indigenous and have a substance addiction.

The committee's Gino Vambuca says diversionary programs would also help to cut prison over-crowding and save money.

"Taxpayers can save over $100,000 per Indigenous offender who's charged and sentenced for a non-violent crime but has a substance use dependency, compared to if they go to prison or treatment," he said.

The report also suggests mandatory rehabilitation is costly and not as effective as community treatment.

Gino Vambuca says the findings are significant for the Northern Territory.

"On some level it's great that the NT government is supporting treatment for people," he said.

"But it can't be mandatory and within prison. That's not the ultimate way to engage people in treatment."

The Northern Territory Minister for Correctional Services says he agrees with the report's recommendation that governments contribute to treatment programs.

But John Elferink says the Territory is one of the cheapest places in the country to keep someone in custody.

"There is a public expectation that people actually are subjected to punishment as well," he said.

"And punishment of course is not something that many people want to talk about in the intelligentsia."