The rapidly-growing prison population has forced the Corrections Department to consider reopening prison units which were closed just a year ago.
The department is also reporting a trend of more women being locked up, which means some female inmates may have to be housed at a unit in Rimutaka Prison, a men's prison.
Corrections said yesterday it was considering reopening the 112-bed Upper Jail Unit at Rimutaka to cater for an overflow of inmates from nearby Arohata Women's Prison, where an expansion is not yet completed.
The unit was closed just last year because the prison population had been forecast to fall. Instead, the prison population is still growing, and passed 10,000 inmates for the first time in November. The closures were a controversial move, with up to 260 jobs lost - though some prison staff were reemployed at other jails.
The Government plans to spend up to $2.5 billion on new prisons and expanding existing ones over the next few years, but in the short term more prison beds are urgently needed. It is understood another prison unit which was closed last year, at Waikeria Prison in the Waikato, could also be reopened to cater for another 240 prisoners.