A lack of staff will see more inmates bring transferred from Christchurch Men's Prison to a facility in Otago.
Corrections said the prison reached "operational capacity" last weekend, which meant one remand prisoner was held in a police cell and six prisoners were sent to Otago Corrections Facility.
It planned to transfer eight more today, and a further eight on Thursday.
National Commissioner Leigh Marsh said there was no shortage of beds, rather an ongoing staffing shortage.
He said there were 944 beds at Christchurch Men's Prison but current staffing levels meant it could only manage 786 people.
"Corrections is managing ongoing staffing pressures, including at Christchurch Men's Prison. When fewer staff are available, we must make very difficult operational decisions - prisoners may spend less time unlocked, or we may temporarily reduce the number of prisoners that a site can accommodate and divert prisoners to other prisons," he said.
Marsh said the prisoners being moved were remand and high security prisoners. He said those prisoners were primarily accommodated at the Otago facility where there was more capacity, as three high security units closed at Christchurch Men's Prison last year.
Marsh said transferring prisoners was not uncommon and part of routine prisoner movements, but he acknowledged it could be very disruptive to prisoners and their whānau.
"All transfer decisions are made on an individual basis taking into consideration the specific needs of the individual," he said.
"Consideration is given to each man's employment, education and treatment needs and the ability for their family and friends to continue visits with them."
Christchurch Men's Prison has 44 frontline vacancies. These roles include nurses, corrections officers, case managers and instructors.
Since October 2022, Marsh said Corrections had been making a concerted effort to recruit and retain staff, including launching a recruitment campaign and continuously working to improve staff safety.
"As a result, we've seen an increase in the number of job applications for new Corrections Officers. As at 9 October 2023, there have been more than 10,200 applications received since 1 October 2022," he said.
"We have also recruited 818 people into Corrections Officers roles, with many more in the recruitment pipeline."