There are three new cases of coronavirus in managed isolation and quarantine (MIQ) facilities, the Ministry of Health says - but none in the community.
It comes as supplementary wastewater testing, carried out this week in response to weak positive COVID-19 results in four cities, returned another negative result - this time in Rotorua.
It follows negative results in Queenstown and Wellington on Thursday. A result from testing of Christchurch's wastewater is still yet to be returned.
"The Ministry's current assessment remains that the weak positive results are likely from recent positive cases in managed isolation or due to recently recovered cases who are not infectious but continue to shed the virus," a ministry statement said.
"There is no risk of infection from COVID-19 in wastewater."
Each of three new cases reported on Friday are recent returnees. Two arrived on Wednesday, May 19 - one from the UK via the UAE, the other direct from Qatar - and one flew into Auckland from India via Qatar on Friday, May 14.
The latter is the contact of a previously reported case.
Four previously reported cases recovered on Friday, bringing the total number of active cases in New Zealand to 23. The total number of confirmed cases is 2306.
One previously announced confirmed case has now been reclassified as historical.
Meanwhile New Zealand laboratories processed another 4747 tests on Thursday, with the total number processed to date now standing at 2,100,168.
