The Government will today announce how it plans to roll-out a much wider, "rigorous" Covid-19 testing regime.
A report was delivered to Cabinet on Monday, from the University of Otago's professor David Murdoch, who leads the government's testing advisory group.
Prime Minister Jacinda Ardern said professor Murdoch's work will " form the basis of a new, rigorous testing regime that will be central to our strategy to control the virus".
Covid-19 Response Minister Chris Hipkins has signalled that rapid antigen testing will play a much bigger role in the new regime.
Hipkins said PCR testing of saliva or nasopharyngeal swabs remains the best way to identify early cases of Covid-19, but it only takes 15 minutes to process a rapid antigen test.
"One of the reasons why we have been reluctant in New Zealand is that they are good at detecting acute infection, but detecting early onset infection, not so good," he said.
These tests could give people false comfort, he said.
However, Hipkins added that rapid-antigen testing has been used during this outbreak and will become a bigger part of the country's Covid-19 response "fairly soon".
Twenty-five of the biggest companies, such as Mainfreight and Foodstuffs have called for emergency approval to import and use rapid Covid-19 antigen tests at critical work sites.
The wanted to jointly import 370,000 rapid antigen tests, to be introduced on work sites around the country within the next week, but needed the government's permission to do so.
However, Hipkins said that will be unlikely within the next week.
On Thursday morning, Otago University Associate Professor James Ussher told the AM Show rapid-antigen tests have a place in screening, given New Zealand was shifting to living with Covid, but warned there was still a need for follow up tests.
"To date we've been pursuing an elimination strategy and that has required the most sensitive tests so we don't miss cases - we've had zero tolerance for that - and as such rapid-antigen testing hasn't formed part of our response.
"There are hundreds of these tests out there and they have vary variable performance with the best being up to 80 per cent sensitive compared with PCR but many performed a lot worse."
He told The AM Show rapid-antigen tests hadn't been used because they haven't been fit for purpose for an elimination strategy which up until now had been pursued in New Zealand.
"Clearly with a move to transition and then to living with Covid there's going to be an important role for these to play," said Ussher.
The clinical microbiologist added it reamined important to get good quality tests and that they were deployed in the right fashion.