An Air NZ staff member has tested positive for Covid-19 after returning from a flight from Japan, and here's what we know so far.

Dr Ashley Bloomfield said today she is the woman referred to yesterday aged in her 60s.

Air New Zealand chief medical officer Dr Ben Johnston said her last duty was flight NZ90 from Narita, Japan, which arrived in Auckland on August 15.

She was now isolating, and other crew and customers who were close contacts were being advised.

E tū head of aviation Savage said the woman had not been to NSW in the past three weeks but has visited two Covid-infected countries since the start of August, including Japan.

The union for cabin crew, E tū was informed late on Wednesday that an Air New Zealand 787 crew member tested positive during routine surveillance testing.

"787 cabin crew, in particular, are at the forefront of bringing New Zealanders home and keeping vital passenger and cargo routes open. They make a lot of sacrifices in terms of their personal freedoms so that Kiwis can stay connected," said Savage.

A wider group of cabin crew are also affected because they crewed on the same flights as the person who tested positive. E tū members on the ground may also be considered close contacts.

All affected crew and workers are being removed from rostered duties and are under Ministry of Health instructions to isolate until they are tested and cleared.

"At times like this, cabin crew rally around to support their fellow crew members. The 787 welfare committee will also do what they can do assist," said Savage.

The airline was working with the Ministry of Health to identify if any other New Zealanders have come into contact with the crew member.

Air NZ has been approached today about how many close contacts the woman has.

She was fully vaccinated, Air NZ said.

Johnston said Air NZ was confident proper protocols were followed, including taking private transport to and from a layover hotel, isolating in the hotel while on layover, and wearing PPE.

The fully vaccinated crew member tested positive on Wednesday, August 18, as part of the airline's regular surveillance testing programme for international aircrew.

She was not part of the community cluster of positive cases, which now numbers 10.

"There are significant precautions in place for our crew operating to international destinations set out by the Ministry of Health, and we are confident our people are following the protocols diligently.

"These include taking private transport to and from their layover hotel, isolating in the hotel and wearing PPE at all times while on layover. Aircrew are also subject to regular surveillance testing where they are tested up to once every seven days. "

Johnston said 82 per cent of Air NZ frontline workers had at least one dose of the Covid-19 vaccine and 80 per cent were fully vaccinated.