The Ministry of Health is undertaking contact tracing and asking some people to self-isolate after a recent positive Covid-19 case arrived in South Korea from New Zealand.
The person had tested positive after arriving to South Korea. But later investigations found the traveller had a 14-hour stopover in Singapore before the South Korea arrival, the Ministry of Health says.
Health Minister Chris Hipkins stressed there's still no evidence of any Covid-19 transmission in New Zealand's community, with all recently identified cases remaining in managed isolation or quarantine.
Today he said the person had no symptoms, but returned a positive test after arriving in South Korea on July 22.
A "rapid test" had been used, which Mr Hipkins says is "recognised as less reliable" than the testing done in New Zealand.
They're looking at getting a second test done to ensure it's not a false positive.
Back in New Zealand, they're undertaking contact tracing for people who flew on the same domestic flight as the traveller, who had headed from Auckland to Christchurch on July 20.
People sitting within two rows of the person have been asked to self-isolate and get tested, identified as "close contacts".
Other passengers are also being contacted to be supplied health information, but aren't being asked to isolate, Mr Hipkins says.
Five household members are also self isolating and will be tested today.
"At this point the risk to public health is considered to be low," Mr Hipkins says, describing the procedures as an "abundance of caution".
Anyone with concerns about their own health is encouraged to contact Healthline.
Director-General of Health Dr Ashley Bloomfield calls the case "puzzling", saying there's no evidence of community transmission to suggest the case could have been exported from New Zealand.
"We've had no positive tests [in Auckland]. Our influenza-like illness rates remain low, lower than usual," he says.
"We've not seen people coming into hospitals... Everyone who comes in with a sudden acute respiratory illness is tested as part of that routine surveillance.
"There's nothing to suggest we have community infection here so it's quite puzzling in that respect. We're just being precautionary and acting as if this is a positive test from here until we've confirmed otherwise."
Also today, Dr Bloomfield confirmed one new Covid-19 case in a Hamilton managed isolation facility.
It brings the total of New Zealand's confirmed and probable cases to 1557.