Pressure is mounting on the government and health officials to explain how many people left managed isolation without being tested for Covid-19 since 9 June.
The Opposition leader says it is an absolute shambles and a "national disgrace'' that the information is still unavailable a week since it was first asked, despite repeated requests from politicians and the media.
The question was prompted by the case of two women being given compassionate leave to travel down the North Island on 13 June to be with a dying parent.
They later tested positive after being allowed to leave isolation without first getting a test.
Prior to 9 June, there was no requirement for those leaving facilities to be tested as everyone had to undergo 14 days of mandatory isolation.
But since then Director-General of Health Dr Ashley Bloomfield's instructions have been for routine testing to take place.
How the border regime was being run has come under harsh scrutiny and led to the prime minister putting Air Commodore Digby Webb in charge of all quarantine and isolation facilities after countless reports of strict rules not being adhered to.
National Party leader Todd Muller said the team of five million New Zealanders had endured so much during lockdown, including losing loved one, and it was "quite extraordinary'' that the government did not keep up its part of the bargain to "absolutely make sure the borders are well managed competently".
National Party leader Todd Muller. Photo: RNZ / Nate McKinnon
"The fact that even today we're in a position that neither the prime minister, nor [Health Minister] David Clark, nor [Housing Minister] Megan Woods can look at anyone in New Zealand and say exactly how many people left quarantine or isolation without being tested is a national disgrace."
Prime Minister Jacinda Ardern said health officials have worked through "some of those details'', but it was up to Bloomfield to provide the answer.
Ardern said there was roughly 4200 people being managed at the border currently.
"We're quarantining the equivalent of a small town in New Zealand at the moment. It is a huge logistical exercise, there is no playbook for this, but the Defence Force is doing a very good job of managing the increase in numbers,'' she said.
Between 10 May and 16 June, there were no positive Covid cases that arrived at the border, but since the two women given an exemption to leave isolation tested positive, the number has continued to grow.
Muller said that in itself was "fascinating''.
"So you have 37 or 38 days of apparently nothing arriving at the border, then an admission that their testing procedures are failing and now we've got this huge surge of them arriving at the border,'' he said.
The Opposition is continuing to call for Clark to lose his job over the "cock-up''.
"In my opinion, the minister should have already been sacked - and the prime minister needs to learn to stand-up and look down a camera and acknowledge failure and be accountable for it, as opposed to being there just when the good times roll,'' Muller said.
Is it legal to charge those returning home?
The National Party has come out against a proposal to charge returning Kiwis for their stay in quarantine or isolation.
Cabinet ministers are considering a co-payment scheme as a way of reducing the cost to taxpayers.
The facilities have already cost more than $80 million and nearly $300m has been set aside to cover the rest of the year.
Muller said non-residents should pick up some of the tab - but not New Zealanders coming home.
"You've got to reach a balance and I think New Zealanders wanting to come home in a time of international stress and crisis - I don't think we should have a scenario that says 'and when you come home we're going to hit you with reasonably additional costs on top of that','' Muller said.
There would be a point, he said, where that may need to be reassessed.
Ardern said whether the government could legally charge people was something that was still being worked through.
Prime Minister Jacinda Ardern. Photo: RNZ / Dom Thomas
"These are New Zealand citizens and permanent residents - they have a right to come home - so there are questions that need to be answered over whether or not you could feasibly from a rights perspective put in a co-payment," she said.
"It's not a straight-forward policy question."
New Zealanders were asked by the Foreign Affairs Minister and Deputy Prime Minister Winston Peters to come home early on when the borders first closed and before the country went into lockdown.
This was because it was expected commercial options for flights would become few and far between.
"Now we're in a situation with very strict border restrictions in place that is coming at a cost to taxpayers,'' Ardern said.
"That has to be balanced against the right for New Zealanders to come home."