Corrections is set to move 75 prisoners into Rimutaka Prison to relieve pressures elsewhere.
It is shifting them around amid severe staffing shortages that have cut inmate access to rehab and education programmes, in-person visits and cut back time outside of cells.
The inmates will be shifted to the Upper Hutt prison from its Mt Eden Corrections Facility and Spring Hill in Waikato over coming weeks, the agency told RNZ.
"Double-bunked cells will be opened to accommodate this intake," said deputy national commissioner Leigh Marsh in a statement.
"As Covid-19 cases in prisons have now dropped considerably across the country, we have been temporarily moving some men and women to different prisons to alleviate pressure on staff at our most affected sites to ensure their health, safety and well-being is not put at risk."
Rimutaka has 615 inmates now, well below its 2018 peak of 1100, he said.
"With the movement of staff to the prison this number therefore remains manageable and will enable us to maintain and increase minimum entitlements (including unlock hours, which mean more time out of their cells) and access to rehabilitation programmes and health services for people."
A recruitment drive had netted 1400 job applications in the last three months.
Upper Hutt lawyer Michael Bott said he was being denied face-to-face meetings with three men being held on remand at Rimutaka Prison.
"We can't get in to see our clients, we are expected to go and Zoom them and it's just not good enough," Bott told RNZ.
It had been this way for weeks, he said.
"What's happening is administrative convenience is trumping fair trial rights."
For one client, he had four large folders and the man wanted to look through them, which was simply not possible by phone or video link, the lawyer said.