The Government will continue to carry out random targeted Covid-19 testing in "hotspots" around the country.
Director of Public Health Dr Caroline McElnay said 4241 tests were processed on Thursday as officials ramped up efforts to get an "overall picture" of the extent of community transmission before a possible lift of the nationwide lockdown next week.
New Zealand on Friday recorded two more Covid-19 deaths, bringing the total number of those who have died to 11. The infection rate continues to slow, with only eight new cases.
Fourteen people remain in hospital, three of them in ICU, two of whom are in a critical condition.
According to McElnay, more previously unknown infections have now been linked to the 16 significant clusters around the country.
On the sites of the random testing, McElnay said they had d been increasing their testing over the past few weeks but were mindful it required people to self-present.
The technical advisory group advised them there should be targeting of "hotspots" where there were higher number of cases, and as a result testing would take place in Auckland, Queenstown, Canterbury and five towns in the Waikato.
"The level of community transmission in New Zealand is currently low and most of the cases ... have links to overseas travel or close contacts of other cases," she said.
DHBs, including in Queenstown, Waikato and Canterbury, were arranging for teams to go out into the community including through mobile testing clinics. They were also undertaking targeted testing to provide further information about community transmission in those regions, McElnay said.
"Yesterday at Pak'nSave in Queenstown, 343 supermarket workers and customers were tested. About half of those tests have already been processed and all are negative to date.
"Today a similar approach is being taken in Canterbury with another 250 people being tested at a supermarket, and in Waikato there's also asymptomatic testing occurring at supermarkets in five towns: Otorohanga, Hamilton, Matamata, Cambridge and Te Awamutu."
McElnay said this was a deliberate attempt to "provide us with increased confidence in our data, and that will help to give us an overall picture of Covid-19 in New Zealand".
Asked about a Christchurch patient who reportedly retested positive after being cleared from self-isolation because they had been symptom-free for 48 hours, McElnay insisted the Government's definition of a recovery was "robust".
"On our website we have our guidance for when a patient is considered to be recovered; it's 48 hours from when they're symptom-free.
"I don't know the details of that particular case ... but that guidance is there and it talks also about a 10-day period from the onset of symptoms."