Covid-19 Response Minister Chris Hipkins is rejecting suggestions Auckland's border is too easy to flout, after two women travelled to Northland and have since tested positive.
Hipkins said the Ministry of Social Development approved, and then revoked, the women's border exemption
The second woman was found on Monday and has been co-operating with contact tracers. Both women are in managed isolation and quarantine (MIQ).
"There was a degree of error in the approval in the first place," Hipkins said.
The mistake in granting the exemption was corrected but only after the pair had crossed the border.
Hipkins told Morning Report he did not have any information on reports one of the women hid in a car boot to cross the border, and said it was up to police on whether car boots were checked at the crossings.
"Given the volume of people who are having to travel and the queues that are already forming they will be relatively efficient in the way they process those queues so they may not be doing a thorough inspection of every vehicle.
"I think the police are doing as much as they feasibly can do."
Hipkins said there were issues with the two women's border exemption but he did not accept Auckland's boundary was porous.
"A land-based border is pretty tricky for a country like New Zealand where a huge amount of our economic activity happens in Auckland."
Freight comes in via the airport and port, and people do have to move in and out of the city, he said.
"We try and limit that as much as we can but it is just the reality."
Alert level decision
Hipkins said the case numbers in Waikato were encouraging as Cabinet decides today whether the region and Northland can down to level 2.
"I want to see the testing numbers in both places."
The Waikato cases are all linked, and the three announced yesterday were already in isolation.
"That's really encouraging for the Waikato," he said.
In the case of Northland, contact tracing is important, and the second woman who travelled to the region is co-operating and providing information on locations of interest and the nature of the activities undertaken while in Northland.
"That certainly helps us identify the risk, isolate the risk, and that increases the chance of Northland being able to come back down the alert levels."
The minister denied Auckland had gone to level 3 too soon, saying the shift down from level 4 had not made a lot of difference.
The rise in cases since then was not necessarily an effect of the level change, he said.
"The people that we're talking about in many cases were moving around at level 4 even though of course we try and ask people not to. So the shift from level 4 to level 3 didn't make a huge difference to this particular group of people in terms of the level of movement that they were undertaking.
The longer you keep people at a higher level of restriction, the more people stop following the rules, he said.
"The rules only work if people voluntarily follow them.
"We don't have the resources to put police officers on every street to make sure people are staying home unless they can leave so we do need to keep the goodwill of the majority of people."