An Auckland Airport worker who has tested positive to coronavirus visited major shopping centres, including a Bunnings Warehouse and Westfield while infected.
The cleaner tested positive just one day after Australians and New Zealanders resumed travel between the two countries without having to quarantine.
Prime Minister Jacinda Ardern said the Covid-positive case, who is fully vaccinated against the virus, was employed cleaning planes from high-risk countries.
The worker was put into isolation as contact tracing began after the infection was detected on Monday.
Prime Minister Jacinda Ardern speaks at an airport in Wellington, New Zealand on Monday
The Airport worker visited a Bunnings Warehouse (left) and Westfield (right) while infected
LOCATIONS VISITED BY POSITIVE CASE
Westfield St Luke's Food Court, Saturday April 17, 12.15pm to 2.30pm
Bunnings New Lynn, Saturday April 17, 2.30pm to 3.50pm
Movenpick Dominion Rd, Saturday April 17, 5.15pm to 7.20pm
16 close contacts have been identified, although that number is expected to rise.
Five household contacts have returned negative test results, the person's work at Auckland Airport is is non-public facing and they do not work anywhere else.
They were fully vaccinated, having received two doses of the Pfizer/BioNTech vaccine in February and March.
This means they are less likely to shed and infect other people.
The worker's most recent negative test was a week earlier on April 12.
'This was a border worker who did work in an environment where they were coming into contact with the planes that are used to transport people from red zones; so from high-risk countries,' Ms Ardern said.
On Monday, thousands crossed the Tasman Sea to enter Australia and New Zealand after the long-awaited end of mandatory quarantine.
There were 15 flights into Auckland and 17 departures.
Passengers are pictured lining up to check in for Qantas flight on Monday to catch flight QF143 to New Zealand on April 19
Under the terms of the trans-Tasman bubble agreement, all states, territories and New Zealand can suspend quarantine-free travel with places that have outbreaks.
But the two nations have made assurances that small outbreaks won't result in the bubble being closed.
'We accept that's going to be part of our journey together. Australia accepts that,' Ms Ardern said on Tuesday.
Ms Ardern has brought in a traffic light system similar to the one used in Victoria, with specific hotspots designated as 'red zones' - meaning people only from that area would be unable to fly.
Recent studies from the Centre for Disease Control showed the vaccines were anywhere between 59 per cent and 90 per cent effective at stopping asymptomatic transmission, despite being highly effective at preventing serious illness or death.
This means a person who is fully vaccinated can still catch the virus and pass it along without noticing any symptoms.
Mr Ardern said the isolation of close contacts of the airport worker was underway.
'What's really important is we knew this was someone who was tested only recently,' the Prime Minister said.
'They were negative on the 12th and then their more recent test was positive. So we've picked them up in that routine screening which is always helpful.'
A sign welcomes travellers to New Zealand at Sydney International Airport on April 19