Two people who arrived in New Zealand from Perth are being treated as casual contacts following the Covid outbreak in Western Australia.

The two people are in isolation until results of their Covid tests are known - but the Ministry of Health says the risk to the public has been assessed as "very low".

The ministry was yesterday contacting 1000 passengers who arrived in New Zealand on direct flights from Perth on April 19, 21 and 23.

"Of those, two people from the same household have let health authorities know they were in the Perth domestic terminal at the time specified in the locations of interest page [in Western Australia]," the ministry said in a statement on Sunday.

"They are being treated as casual contacts and have both had their tests today, with results due this week. The risk to the public has been assessed again to be very low. They remain in isolation until their test results come back."

It comes as there are zero new cases in the community and zero new cases in managed isolation facilities today. Two million tests have been processed in New Zealand since February 2020.

There are 33 active cases in New Zealand.

Quarantine-free travel between Western Australia and New Zealand remains paused after Perth and the outer-metropolitan area of Peel were placed in a three-day Covid lockdown on Saturday.

New Zealanders in Australia are asked to follow local guidance and check for places of interest outside of Western Australia.

Passengers flying to New Zealand from other Australian states will be required to complete pre-departure and arrival declarations advising whether they have been in Perth or Peel since April 17, and whether they have visited any of the current locations of interest.

Close contacts of airport cleaner

Meanwhile, the number of close and close plus contacts of the Auckland border worker - an airport cleaner - who tested positive on Tuesday last week has increased to 39, up from 36.

"All 39 close contacts of this case have been contacted and are self-isolating," said the ministry.

Of the 39 close contacts, 34 had returned negative tests to date. Results were still coming on the other five.

"Public health officials are in daily communication with all contacts to monitor their health and confirm any upcoming testing dates."

NZ tests

New Zealand has now completed two million tests for Covid, the Ministry announced.

"The total number of tests processed by laboratories to date is 2,000,842."

The first test was carried out on February 7 last year and the country reached one million tests in October.

Since February 7, a total of 1,212,328 people have been tested – meaning nearly a quarter (244 out of 1000) of all New Zealanders have been tested.

"The highest number of tests completed in a single day was 25,007, during the Auckland August cluster.

"On Saturday, 3620 tests were processed. The seven-day rolling average up to yesterday is 4029 tests processed."

The ministry said the testing, public health measures, and vaccination roll-out were keys in New Zealand's elimination strategy.

"To everyone who has played their part, whether at the frontline or providing necessary support, we thank you for your contribution and the huge difference you've made to our response. New Zealand's response owes a debt of gratitude to our laboratory workers and all other supporting workers who have made this happen.

"We would also like to thank all New Zealanders who have been tested, including our frontline workers who are regularly re-tested."

Community cases

There haven't been any new community cases of Covid-19 for nearly two weeks but the country was put on alert after news on Friday that West Australian city Perth and the Peel region were diving into a three-day lockdown after authorities discovered two infected people had been in their community for five days.

New Zealand's quarantine-free travel was immediately suspended with the Ministry of Health saying it would monitor the situation along with its Australian counterparts.

"About 1000 passengers who have arrived in New Zealand on direct flights from Perth on April 19, 21 and 23 are being contacted and provided with advice," the Ministry said on Friday.

However, health teams deemed the risk of infection low on Friday.

Quarantine-free travel had continued successfully, so far, with the rest of Australia.

Flights to Perth resumed yesterday while the return service, NZ176, was renumbered and will operate as a cargo-only service.

Flights NZ175 from Auckland to Perth and NZ176 from Perth to Auckland tomorrow were delayed 24 hours. Both will depart on Tuesday subject to the restrictions in Perth being lifted.

People booked to travel between New Zealand and Western Australia this long weekend were urged to check what needed to be done through their airline.

"Passengers flying to New Zealand from other Australian states will be required to complete pre-departure and arrival declarations advising whether they have been in Perth or Peel since 17 April, and whether they have visited any of the current locations of interest."

"If people have been to a location of interest they should stay at home, or in their accommodation, and get a test."

The Ministry had also been hoping anyone flying into the country through the transtasman bubble had been signed up and using the NZ Covid Tracer App.

The tracer app now has 2,796,868 registered users.

Poster scans have reached 255,551,347 and users have created 9,558,417 manual diary entries.

There have been 793,998 scans in the last 24 hours to midday on Saturday.