A Launceston Magistrate told a defendant this week they would be unlikely to access the program because it was above capacity.

The program offers a sentencing alternative for defendants, whose drug use is linked to their offending.

In the North, the program is capped at 20 places but more than 30 people are currently using the service.

“It’s as full as I’ve ever seen it,” Magistrate Sharon Cure said.

The state government announced an increase in June this year, promising an additional 40 spots statewide as part of a $1.3 million budget allocation.

Acting Corrections Minister Guy Barnett said the funding would allow for an extra 15 places in the North, which takes the total to 35.

It is unknown when the new places will open.

“This funding recognises the important role that rehabilitation and treatment programs play in ensuring community safety,” Mr Barnett said.

“We will look to expand the program even further as the phase out of suspended sentences progresses.”

Tasmanian Prisoners Legal Service chair Greg Barns said it was “not enough”.

“It is a breach of a person's human right if they are unable to access proper rehabilitation programs, through no fault of their own, simply because the government refuses to put adequate resources into reducing crime,” he said.

“Instead of wasting money on jailing more people and funding an overcrowded prison, those resources could be better spent on ensuring individuals have access to diversion programs. It would be a much better use of taxpayers money.”

Mr Barns said diversion programs had a “much better track record” at reducing crime than imprisoning offenders.

“Recidivism rates are much lower for those who complete diversion programs. If you want to increase crime then keep jailing people,” he said.