The Government has unveiled plans to build three new prison drug treatment units by the end of 2011.
It has given the Corrections Department enough funding to double the number of prisoners receiving drug and alcohol treatment.
Participation in such programmes will thus be extended to 1000 prisoners annually.
Corrections Minister Judith Collins says new units will be built in Otago and Wanganui prisons in the next two years, and another will be built in the northern region, possibly at the new prison planned for Wiri.
She says the new units take the number of drug treatment programmes available in prisons to nine.
Corrections Department chief executive Barry Matthews says abridged alcohol and drug programmes will also be introduced so that prisoners serving shorter sentences can attend.