Covid-19 Response Minister Chris Hipkins has confirmed the government is working to give retailers permission to sell rapid antigen tests.
The government has 7.2 million rapid antigen tests in New Zealand now, and some 22.5 million are expected to be in the country by the end of February.
The government supply of tests is made available to businesses deemed critical services, but some companies, like Foodstuffs, have managed to secure their own which they want to sell.
The approval process for the tests in New Zealand included a high threshold for accuracy, but was "moving very quickly", Hipkins told Morning Report.
"We have a higher threshold than Australia does, and I note that Australia are now reviewing some of the tests that they have approved because of concerns that they're not accurate enough and that actually they may be contributing to the spread of Covid-19 rather than the prevention of it."
"The threshold that we have is that those tests have to be at least 80 percent accurate because even at 80 percent you're still potentially missing one in five cases.
"We won't approve tests that have a lower accuracy rate than that because they have the potential to do more harm than good."
Hipkins said the government was working through when to allow retail sales.
"I think that you'll see some change on that front fairly soon, but again, there there are going to be international supply constraints there.
"And I suspect they're not going to end up being cheap when retailers do end up selling them. "
He would not say how soon the tests may be available in supermarkets. "I'm not making announcement on that today - it's something that we're working through."
He said stockpiling tests available earlier would have meant many were unusable by now.
"Around that time that we were putting in our first orders for rapid antigen tests, many of the tests we were able to get hold of only had a shelf life of around six months or less even, and so if we stockpiled them at that point many of those just wouldn't be able to be used now, they'd be heading off to the landfill.
Hipkins said the government supply of rapid antigen tests was targeted to those who need to be in work in order to keep things moving.
"Businesses are able to order and and use their own tests when they can get them. But it is of course proving to be very challenging for them to get hold of them as well."
On the steps required for critical businesses to get hold of the tests, Hipkins said the process was to make sure those with the highest levels of needs had access to tests when they needed them.
"In the case of large businesses, for example, some of those large businesses have been getting their stocks of rapid antigen tests in advance to try and smooth that process."