Christchurch's Rolleston Prison is to be made available to house emergency services staff working on the earthquake search and rescue operation.
A shallow 6.3-magnitude quake struck at 12.51pm on Tuesday, 10km south-east of the central city, causing many deaths and widespread devastation.
The Corrections Minister, Judith Collins, says all three prisons in Christchurch have come through the earthquake fine.
She says prisoners from the low-security Rolleston Prison will be transferred to Christchurch Men's Prison.
Ms Collins says 250 extra police from around the country are being deployed in Christchurch, and Australia is also sending 200 officers to assist.