The link between the case and the border or managed isolation has yet to be established, the Health Ministry said in a statement on Tuesday, adding the case is now being investigated.
The Auckland Regional Public Health unit is undertaking interviews with the infected person for contact tracing purposes, the statement said.
Anyone in Auckland catching public transport on Tuesday or who cannot socially distance in public spaces should wear a mask as a precaution, the ministry said.
“Ministers will meet this afternoon once additional information is gathered to confirm a response,” it added.
New Zealand’s tough response to the pandemic has helped it virtually eliminate COVID-19 domestically, allowing people to live without restrictions, although its international border remains largely closed.
The country has reported about 2,500 confirmed cases of coronavirus and 26 related deaths.