There is concern unnecessary pressure is being put on managed isolation facilities because New Zealand's pre-departure testing is not up to scratch.
Leading epidemiologist Professor Michael Baker is warning if it's not sorted, it's just a matter of time before there is another breach at the border.
Airports and airlines around the world are using the latest technology in a bid to stop the spread of COVID-19. But there's growing alarm at how many people are still testing positive straight after arriving in New Zealand.
"I think it is very urgent. It's our number one area of vulnerability," Baker says.
Managed isolation is our last line of defence against COVID-19 getting into the community.
On Monday, 11 new arrivals - 10 from India via the United Arab Emirates on the same flight - tested positive on their day zero to one tests.
"We really need to put more effort in turning down the tap of those source countries, because this is the thing that will drive our risk of outbreaks in New Zealand," Baker says.
Prime Minister Jacinda Ardern says whenever they see those numbers, particularly if there's a pattern around an airline, "we do and we have asked questions".
For the past two months, anyone wanting to enter New Zealand has had to produce a negative COVID-19 test certificate.
Rumours of people buying fake test results have been circulating, but Ardern and Baker say there's no evidence of that happening here. But Baker does say much more information about how testing is done is needed.
"What labs are doing it? When's it being done, what are the test methods?"
At the moment, a returnee needs to test negative within 72 hours of departure. Baker says it's too long to potentially contract COVID.
"The other thing we could also consider is introducing pre-departure rapid antigen tests at the airport before they get on the flight."
Ardern says there are no plans to strengthen the testing regime.
"We have never relied on pre-departure testing as being foolproof, that's why as soon as someone arrives in New Zealand we test them immediately again," she says.
"That's providing the extra layer of assurance that we've got people in the right facilities if they happen to have COVID."
Baker argues that stopping them before they can even bring it into the country is a better solution.