WELLINGTON -- Whole genome sequencing results for a recent returnee have confirmed the South African variant, B.1.351, New Zealand's Ministry of Health said on Monday.

The woman who recently traveled from overseas and completed their stay in managed isolation in the Pullman hotel in Auckland has subsequently tested positive for COVID-19, Minister for COVID Response Chris Hipkins told a press conference.

"We continue to monitor advice from the World Health Organization on this variant. Currently there's limited epidemiological data available on the B.1.351 variant, making it harder to study. The preliminary concern of this variant is that the mutation affects the body's immune response to it and its transmissibility," Hipkins said.

"New forms, or variants, of the virus have become increasingly common around the world, and we have expected to see them here in New Zealand," he said.

The woman and her only close household contact are isolating at their home south of Whangarei, he said, adding that the Northland District Health Board Medical Officer of Health has undertaken an assessment of the case and their close household contact, and it has been determined that the pair are currently able to isolate at home. The situation will be monitored closely to ensure there is no public health risk.

Following a further interview with the woman, contact tracing has now found the woman has 15 close contacts. All contacts are self-isolating and have been tested, the minister said.