Four cases of community transmission were found from the same family which has no history of international travel. Auckland was put into lockdown and Alert Level 3 for three days until midnight on Friday and the rest of New Zealand to Alert Level 2.
A retirement village also went into lockdown after residents showed symptoms of respiratory illness, according to Sky News.
"We're asking people in Auckland to stay home to stop the spread," said Ardern, according to Sky News. "Act as if you have COVID, and as though people around you have COVID."
"As we’ve been saying for several weeks, it was inevitable that New Zealand would get another case of community transmission," said the New Zealand Health Ministry on Tuesday. "We have been working on the basis that it could be at any time – and that time is now."