LSG Sky Chefs, which services at least 34 airlines around the world according to its website, including Air New Zealand, has shut its laundry department in Auckland after a staff member tested positive for Covid-19.

The staff member, her tradesman husband and Year 9 Papatoetoe High School daughter are the three new community Covid-19 cases in South Auckland reported yesterday.

"As an immediate action and pre-emptive measure, and as part of our internal pandemic plan guidelines, we closed the very small laundry department at our Auckland facilities on February 14," an LSG Sky Chefs spokeswoman said.

"All employees working there were asked to get tested and to self-isolate."

The company employs around 270 people in its Auckland facility; eight of them work in the laundry section.

The spokeswoman would not say which airlines use its laundry section services.

"As a matter of principle, we are not talking about individual details of our customer contracts and hence cannot reveal any customer names in this matter. Thanks for your understanding," she said.

Air New Zealand this morning said the company did not provide any laundry services for the airline. Its chief customer and sales officer, Leanne Geraghty, said the airline was not uplifting any food or catering items from LSG Auckland while the cases were investigated.

LSG Sky Chefs said in general all frontline workers with face-to-face contact with crews and travellers received and wore Personal Protective Equipment consisting of a mask, gloves, sleeve protectors and aprons.

"Although the laundry and dishwashing areas do not have said face-to-face contact and also no access to the airport or to aircrafts, we also provide our employees in these areas with said PP equipment to protect them as much as possible," the spokeswoman said.

She said these employees were included in its regular surveillance testing process.

"This has been done for precautionary reasons and for the safeguard of our employees as these areas are handling items that are offloaded from incoming flights.

"As a matter of principle, we follow the current national guidelines in our catering facilities when it comes to social distancing, wearing masks...our employees are regularly trained in hygiene measures, such as thorough hand washing, which is also part of our standard food safety and hygiene procedures."

She said the company had received no information since February 5 of any other employees feeling unwell.

"The health and wellbeing of our employees are our utmost priority.

"Since the beginning of the pandemic, we have implemented our internal pandemic plan in all our catering facilities worldwide, in addition to the national regulations, to safeguard our employees as much as possible while they are working for us."

A Ministry of Health spokeswoman said Dr Ashley Bloomfield would address the LSG Sky Chefs situation at the 1pm Covid press conference today.

The origins of the latest Covid cases are still unclear.

"We do still have people who transit through New Zealand and fly on to other destinations. They stay airside but of course, it means they are using the things that go through the laundry at this individual's place of work," Prime Minister Jacinda Ardern told Newstalk ZB this morning.

"The other possibility is that it's international airline crew... they also do the laundry of a couple of international airline crew. And so, that is also one of the possibilities."

It was still possible - but unlikely - the new cases had come from an MIQ case which hadn't been sequenced, Ardern said.