The Ministry of Health confirmed in a statement that the person in question is a worker at Auckland Airport. Authorities say the case had nothing to do with the trans-Tasman bubble and that it was highly improbable it would affect movement.
The worker who tested positive had been cleaning planes arriving from red zone countries which turned out to carry infected passengers.
"This is also someone who is part of routine testing". She reiterated people who are vaccinated can still get Covid-19 "but they won't get sick and they won't die".
Ms Ardern said the fact the worker has tested positive after being vaccinated is a "really important opportunity to point out that the vaccine is 95 per cent effective at reducing symptomatic onset". So they were last tested on the 12th and then the 19th. "New Zealand knows how to deal with this".
Ardern said people can still get Covid-19 after being vaccinated, but it would make them a lot less sick than otherwise.More news: Walter Mondale, Former Vice President and Failed Presidential Candidate, Dies at 93
It comes on day two of the trans-Tasman bubble after more than 1,800 Australians touched down in the country without having to quarantine.
"As vaccine rollouts happen, both here and elsewhere, that's what's going to happen".
Earlier today the Ministry of Health revealed that a new border-related Covid case has been detected on the second day of the transtasman travel bubble.
She said she has not spoken to Australian Prime Minister Scott Morrison about this case, but Health Minister Andrew Little has spoken to his Australian counterpart.
The person was tested regularly because they worked in an area of high risk, Ardern said.More news: Australia-New Zealand travel bubble off to fast, emotional start
"And as we know this virus is very hard to contain, and I think the public should be reassured that there are very good health and safety regulations in place". "And it was their most recent test in which this case has been picked up", Ardern told media as reported by ABC News, saying that this showed how the protocols were working as the government had intended.
The person has been tested weekly for Covid-19, and had previously returned negative tests prior to today's positive test, which was carried out at their workplace yesterday.
New Zealand's Ministry of Health confirmed the individual was now in isolation and the case would not be classified as a locally acquired case and instead a "border case".
The case appears to be unrelated to the travel bubble though and flights with Australia have not been suspended.More news: Guelph police not conducting random stops, clarify role in provincial guideline enforcement