The Government says it will not be releasing prisoners from jail early as a way of easing a prison bed shortage.
Corrections Minister Judith Collins announced on Monday that 8,509 people were being held in prisons or police stations nationwide - a record high.
The minister's release of the figures coincides with court action by the union representing prison guards regarding plans to increase the use of double-bunking in jails.
Ms Collins says it is predicted the Corrections Department will run out of baseline beds by early next year and double-bunking is the only option.
"It's something we've been talking about for a long time," she says. "Twenty-one per cent of our cells are already double-bunked, and it's standard use all round the world."
The Labour Party's law and order spokesperson Clayton Cosgrove says however that the warnings about the urgent need for more prison beds are a sham.
He says the Prison Service still has 500 beds available for use before it reaches capacity.
Ms Collins says however that the count underlines the urgent need to anticipate further increases in the prison population.
She says the Corrections Department has been asked to speed up the process of adding on to existing prisons, including building a 60-bed container cell block at Rimutaka Prison in Wellington.