Prisoners have been sent to work at a salt mine in central Australia after the company had trouble recruiting staff.

Northern Territory Correctional Services Minister John Elferink says the potash project near Curtin Springs, about 250 kilometres south-west of Alice Springs, is now training prisoners being provided by the Territory Government after failing to find staff.

He says the company is paying award wages, which go towards costs such as salaries for security guards.

Mr Elferink says the prisoners are covered by workers' compensation insurance.

"I expect prisoners in the Northern Territory corrections system to work," he said.

"If they are particularly good at what they do, then we reward them with full-time work outside the prisons.

"So, if they work inside the prison, they will ultimately work outside the prison."

It is not known how many prisoners are working at the site.

The potash project is a joint venture between Rum Jungle Resources and Reward Minerals.

The Country Liberals Government introduced its 'Sentenced to a Job' program for prisoners in Territory jails earlier this year.

They can be used to work on both public and private projects.

Only prisoners in the lowest security classifications can take part in the scheme.

Of their earnings, 5 per cent goes to a victims' assistance fund and $125 a week is deducted to cover their board costs in jail.

The prisoners get $60 a week in spending money, and the remainder of what they are paid is put into a trust fund and they are paid a lump sum when released from custody.