A team of Covid-19 testers has travelled to Stewart Island after a child who lives there returned a weak positive result after having a pre-departure test ahead of overseas travel.
The rest of the family returned negative tests and so did the child when they were re-tested.
Now health officials are waiting on the results of serology tests to rule out an old infection - but suspect that the weak result could be a false positive.
As a precaution a child care centre has been closed for now.
The Director General of Health Dr Ashley Bloomfield said because Rakiura is isolated, the community needs reassurance so the district health board has mobilised a testing team.
Chair of the Rakiura Community Board Jon Spraggon told Checkpoint that testing has been underway today and is due to be finished tomorrow at the local community centre.
Children from the preschool are being tested along with anyone who feels unwell.
He said all up there are about 50 children of primary school and preschool age on the island.
Spraggon has visited a community office at the library today and said the facility was being given a deep clean.
"So the steps are being taken but hopefully it's nothing.
"We would hate to see it come to the island - as any community would."
He said because it was such a small community in theory anyone could have come into contact with the family whose child returned the weak positive result.
There are many seniors on Rakiura and there is a sense of disappointment that hardly anyone has been vaccinated. Around a quarter of the 400 residents are aged 65 or older, he said.
"It was hoped that they [health officials] would come to the island and do it because it's pretty expensive for people to have to go to town to have it and the suggestion is they would stay overnight."
He said he would like to see the vaccinations sped up for older residents as well as staff working with customers of the ferry and airline services.
"The majority of people I think are keen to get it."