Isolation for the prisoners will end when lockdown lifts tomorrow morning.
Deputy National Commissioner Andy Milne said the man who was tested for Covid-19 was in isolation at the Rotorua police hub and none of the prisoners had close contact with him. "We have robust plans in place to mitigate the risk of any infectious illness spreading in prison.
"The secure and controlled nature of the prison environment means we are able to quickly isolate any prisoners, restrict movements, and identify those on site who would have been in contact with any unwell individual should this be required."
Eleven staff were quarantined at home, including a contracted doctor, a nurse and nine custodial staff.
Milne said the prison took a deliberately cautious approach on the advice of the Ministry of Health, although no prisoners or staff were symptomatic.
Visits to Waikeria Prison were cancelled tomorrow when the prisoners were in isolation, but are now expected to continue.
"We remain vigilant in ensuring that prisoners and staff are well informed about the symptoms of Covid-19 and how to prevent infection from spreading, and will continue to reiterate the importance of this," Milne said.
Bay of Plenty Police Association director Scott Thompson earlier told NZME he was pleased Rotorua senior staff had taken a proactive approach. "Erring on the side of caution to ensure our staff are kept safe from any potential risk is a good thing.
"It's only what our staff would expect and also what any employer should do," he said.