The Government can't say for sure that Aucklanders haven't been flying out of lockdown against the rules and seeding COVID-19 across the country.
At least 19,000 passengers have been through domestic and international terminals at Auckland Airport since level 3 restrictions were put in place earlier this month.
Under level 3 you're supposed to get an exemption from the Ministry of Health, or fit certain criteria listed on its website, and you have to prove it to the Aviation Security Service.
But Newshub Nation has been told of three cases of where documentation didn't meet the criteria, or wasn't checked at all - and yet those Aucklanders just hopped on the plane.
So how locked down was Auckland's lockdown?
Newshub Nation asked the Ministry of Health and the Government to assure us that nobody got out who shouldn't have.
"It's very clear that the responsibility in terms of Auckland Airport lies with the Aviation Security Service," said Finance Minister Grant Robertson. "The Ministry of Health, as you're noting, provides the paperwork that people then use. You'll understand that while those are connected they're not the same organisation."
So Newshub Nation went and asked the Aviation Security Service. They told us staff should ask why someone is travelling and sight any documentation.
The Ministry of Health did not ask for that information to be collected, it therefore can't go back and check whether people who left Auckland had the correct documentation, or even whether it was checked.
They don't know how many people were refused travel - unless they were referred to police.
Police told Newshub Nation they have been called in four times.
The point is New Zealanders are told restrictions are in place, but the data to prove it - as far as we know - isn't there.
The Government has not been able to prove that Aucklanders who don't meet the criteria have been prevented from flying to other areas in New Zealand - and potentially taking COVID-19 with them.
There are currently 131 active cases of COVID-19 in New Zealand - 18 in managed isolation and quarantine facilities, one in Waikato and the rest in the wider Auckland area.
Despite a handful of cases still being found each day, Auckland is set to move to level 2 on Monday - and officials are hoping their much-improved contact tracing systems will keep the local outbreak under control.