Corrections has paid about $2 million over 18 months on hotel rooms for extra guards at Mt Eden prison.
Corrections needed extra guards when it took over the management of Mt Eden Corrections Facility (MECF) last year.
Video footage of "fight clubs" within the Serco-run prison were posted online in July 2015, sparking an investigation by Corrections' chief inspector and eventually leading to the decision to end Serco's contract.
Corrections northern regional manager Jeanette Burns said the department had been rotating staff from around the country to Mt Eden for the past 18 months to improve safety.
Some were in Auckland, but others needed to be put up in accommodation, including the four-and-a-half star Adina Hotel.
"Given the duration of stays, a flat discounted rate has been negotiated with the hotel. The price negotiated is commercially sensitive but is a significantly discounted price."
Burns said costs would be met out of a settlement reached with Serco.
"Corrections is running a national recruitment programme and this is going well. Following training of new staff the existing staff who have been seconded to work at MECF will be transitioned back to their home sites."
Act leader and Epsom MP David Seymour said he understood the situation that had faced Corrections after it took over the prison at short notice, but to keep paying for accommodation for 18 months "shows a certain amount of inertia and perhaps a disregard for taxpayers' money".
"Bear in mind that just about every principal in Auckland has a major problem in finding accommodation for staff, but they don't put them all up for hotels for almost two years."
Seymour did not think it mattered that the costs were being met from the Serco settlement, saying it was still money available to the Government.