The Corrections Department has beds available for emergency use but will run out by February, Corrections Minister Judith Collins says.
Ms Collins yesterday released information showing the number of prisoners in New Zealand was at the highest level ever.
There were 8509 people in prisons or police stations nationwide yesterday – 16 higher than the previous peak of 8493 prisoners on September 7.
The high number underlined the "urgent need" for more beds in the form of container cell blocks and double bunking, she said.
There are some beds available for emergencies, "should there be a civil disaster like an earthquake or something like that that takes out a prison".
"What we can't do is to have it so there are no beds anywhere in the country available."
But by February there would be no beds, Ms Collins said.
She was working with the Justice Minister to find a solution, but "in the mean time, as Minister of Corrections, we've got to start housing people".
"Frankly, we've got a crisis to deal with and I can't wait until February next year to say `by the way, I've got no beds'."
Labour law and order spokesman Clayton Cosgrove said the timing of the announcement, while the union of corrections officers was taking the Corrections Department to court over double bunking, was no coincidence.
Ms Collins said she released the information when it became available.