A child on Stewart Island has returned a weak positive Covid-19 test result.
Officials are now investigating whether it is a historic case or a false positive.
As a precaution the Rakiura Rugrats early childhood centre will be closed for the rest of the week.
Director general of health Dr Ashley Bloomfield said the result was picked up when Stewart Island family had Covid tests before planning to head overseas. A second test was negative and other members were also negative.
"Everything points to this being a false positive," Bloomfield said, but officials wanted to confirm this with serology testing, the results of which are due this afternoon.
Bloomfield said that during lockdown last year there were quite a few Covid cases that health teams never knew about so the Stewart Island positive test could be a historical case.
Stewart Island/Rakiura local board chairman Jon Spraggon said he was informed this morning about the weak positive case.
He was told that health officials would be visiting the island this afternoon.
The Rakiura Rugrats childcare centre manager declined to comment.
The Ministry of health said today a subsequent test of the person was negative. Their family members also tested negative.
Possible contacts had been asked to isolate until further information was available and a community testing station is now open at the island's Community Centre, primarily for those with symptoms and anyone linked to the childcare centre.
"Public health staff have so far been unable to identify any likely source of infection," the ministry said.
"Any local residents seeking testing are expected to be able to be accommodated."
PM reveals when you can expect to get your Covid vaccines
Prime Minister Jacinda Ardern today set out the timeframe for the rollout of the Covid-19 vaccination programme.
She said it started by targeting those at high risk, including frontline workers at the border and those aged 65 or over. Nearly 1 million doses have been administered.
Most of New Zealand's vaccines would arrive in weekly shipments from the end of next month, when the programme would broaden considerably, Ardern said.
The bulk should arrive by the end of October, Ardern said.
The rollout would work from the oldest members of the population down to younger members, with priority for the over-65s.
"We've landed on age bands because it is the simplest process used overseas," Ardern said.
Those under 35 can expect to wait until October for jabs
The first age band is people aged 60 years and over, starting from July 28.
The next age band will be 55 over, starting on August 11.
The 35s and over will be from mid-September. Everyone else will follow in age bands from October - although places like the Chatham Islands would probably all be vaccinated at once.
An online invitation would guide people through the process on the Book My Vaccine Website. There would also be a phone line service for those that did not wish to use online services.
The website has been tested to ensure it was up to the task - it already has 26,000 active bookings - Bloomfield said, but it would roll out to DHBs at different times.
People would be asked to complete their second jab within three weeks of receiving their first, which was different to many other parts of the world, Ardern said.
"Everyone will have the chance to be vaccinated."
Those worried their details were not up to date could visit a government website from the end of July to update their details and ensure they got their invitation.
The ministry was also looking to work with big companies to roll out vaccine programmes. Companies such as Fonterra and Mainfreight had already indicated they were willing to assist.
Aim for 300,000 doses a week
Ardern called on the team of 5 million to do their part in the vaccine rollout, just as they have done in the Covid-19 lockdowns.
"This is about whānau, looking out for each other and ensuring everyone is safe."
Bloomfield said health teams expected to receive doses of Johnson & Johnson's Janssen vaccine from August, depending on approval by health authorities and Cabinet.
"[It] had been through a lot of testing," he said.
Ardern said like the flu vaccine every year, the Covid vaccine programme would also likely need to be updated.
However, Bloomfield said no country had yet developed an updated vaccine for Covid.
Bloomfield said there has been a whānau approach taken to vaccinating Māori and Pasifika people, which meant other family members could also be vaccinated with older relatives.
Ardern said she was looking forward to getting her first vaccine jab.
Ardern said mass vaccinations and large workplaces would also be used to reach Māori and Pasifika communities earlier, along with certain rural and isolated communities.
In the past vaccines couldn't be stored for as long and so vaccinators relied on walk-ins at the end of each day to use leftover vaccines.
However, approval had been granted to store vaccines longer so walk-ins were no longer needed as much or encouraged.
Ardern said New Zealand was watching closely how other countries opened up to travel as their vaccination programmes reached different stages.
New Zealand epidemiologists were also studying and modelling the issue, she said.
Ardern said having as many people vaccinated as possible would give the country the greatest freedom possible.
"If we have as many as possible vaccinated, that reduces risk and gives us a chance to change things at our border," she said.
Experts were currently discussing when borders could be opened.
Other countries were writing their rule books now about how to do this, but New Zealand still had to write it own rule book because of its earlier Covid elimination strategy.
Ardern said a lot of countries, especially within the European Union, were only opening up to travellers who had been vaccinated.
Ardern said most Kiwis would expect a similar policy in New Zealand.
Ardern said New Zealand was closely linked in with international work at potentially using and providing vaccine certificates in the future.
Today's announcements come after multiple reports of issues with current booking systems, specifically in Auckland.
On Wednesday, the NZ Herald reported stories of people's records being lost after their first vaccination, centres being booked out until August and people waiting up to eight weeks between their two doses.
Ryan (not his real name) told the Herald his 82-year-old father, who lived with a serious lung condition, was told mid-August was the earliest he could book at the Birkenhead centre, the closest o his North Shore home.
When Ryan's father asked whether he could get an earlier appointment at another centre, he was allegedly advised it was safer for him to wait, given his health.
It was in stark contrast to Ryan's experience in Rotorua where he contacted his DHB and was vaccinated within four days.
A Northern Region Health Coordination Centre (NRHCC) spokesperson admitted it was possible some people in rollout priority groups 1-3 may be waiting until August for their jab.