Ardern told RNZ the positive test originally returned for the person was "what's called a high CT" result. Retesting because of this has shown a negative result.
She said a positive high CT test result may show up for a number of reasons, including the possibility the person may have Covid-19 antibodies from a historic infection.
Countdown Katikati, the only supermarket in the area, closed for a deep clean yesterday, after being named a location of interest in relation to the person who travelled from Auckland.
A Countdown spokeswoman said staff at the store followed all the recommended health and safety procedures.
"This included closing our Katikati store for a deep clean yesterday afternoon," she said.
"This is in addition to the thorough cleaning that is undertaken during each day, which has been further increased with the changing alert levels we have seen since August."
While it had been an unsettling weekend for the Countdown Katikati team and local community, the Katikati case returning a negative result was welcome news.
"We're really grateful to the local community for their patience and support - it has meant a lot to our Katikati team.
"The store is back open today and we'd encourage customers to keep up the good work by continuing to scan in and wear their masks whenever they are in store."