Prime Minister Jacinda Ardern's government has been accused of risking the health of New Zealanders after revelations most people allowed to leave COVID-19 quarantine in June did so without tests.
Of the 55 Kiwis granted compassionate exemptions to leave isolation between June 9 and 16, all but four did so without a coronavirus test.
The Ministry of Health admitted the failing in an after-hours press release after a week unable to answer questions on its testing regime.
Opposition leader Todd Muller seized on the declaration, calling it a "national disgrace" and asking besieged health minister David Clark to resign.
"The minister of health ultimately has been accountable (and) must step down," Mr Muller told Radio NZ.
"If the net effect of all of those lapsed protocols is that we avoid community transmission, we are indeed a lucky country."
Mr Clark previously offered to resign after being caught making multiple lockdown breaches, however Ms Ardern refused it, saying disruption in the portfolio was undesirable during the crisis.
The compassionate exemption system was introduced to allow Kiwis to see terminally-ill loved ones or attend funerals after racing home from overseas.
The revelation that two women were granted releases without being tested - only to test positive last week - prompted Ms Ardern to pause and review the exemptions regime.
Siouxsie Wiles, a University of Auckland microbiologist who has become one of New Zealand's most trusted figures through the crisis, said the chances of COVID-19 returning to the community through an exemption was "very low".
"It's not the testing, it's about the isolation ... the isolation is our best defence," Dr Wiles said.
Since re-booting the testing regime in the past fortnight, health officials have turned up 12 positive tests.
Under the government's coronavirus elimination strategy, all international arrivals have been asked to isolate for a fortnight to minimise the risk of the deadly virus spreading back into the community.
More than 21,000 arrivals - with Australia the most popular country of departure - have gone through a fortnight of isolation, which is managed and paid for by the government.
New Zealand has spent $NZ81 million ($A76 million) on the quarantine regime to date - costing around $4000 per person - with another $NZ298 million ($A279 million) budgeted for the rest of the calendar year.
Australian Associated Press