There are 2 new Covid-19 cases in managed isolation and no new cases in the community. The seven-day rolling average of new cases detected at the border is 4.

The total number of active cases in New Zealand as of Tuesday is 80, a Ministry of Health spokeswoman said.

The two new cases travelled together and arrived in New Zealand on the same flight as the 10 new positive Covid-19 cases reported yesterday. They have been moved to the Auckland quarantine facility.

They returned a positive result after day 1 testing.

"These recent positive cases do not necessarily indicate an issue with pre-departure testing, since people may not have been infectious at the time of pre-departure testing," the spokeswoman said.

"They may have been incubating the virus at the time or be exposed to the virus after being tested.

"The Ministry does not consider these recent cases from India as entirely unexpected, given India is reporting the highest number of daily Covid-19 cases worldwide at present. These cases again underscore the value of having the day 0/1 testing in place. All people arriving into New Zealand must remain in their rooms until those day 0/1 tests results come back."

Meanwhile the total number of confirmed cases so far is 2139.

The investigation into the Day 12 case at the Grand Mercure managed isolation facility in Auckland continues.

The total number of returnees in this group has increased to 344 as it includes the last returnees who needed additional monitoring to leave the hotel. They are now isolating at home until they return negative test results. The assessment was that this additional step was needed until yesterday, and it has now been lifted for anyone leaving the facility from today.

As at 9am Tuesday, 340 of the 344 returnees to have left the Grand Mercure have been contacted. Of those, 315 have returned negative results, one returned a positive result which is classified as a historical infection on the basis of further testing and serology results. Historical cases are not considered to be infectious. There have been no results yet for 28.

It comes a day after the Ministry of Health announced 11 new cases of Covid-19 in managed isolation. There were no cases in the community.

Of the 11 returnees to test positive yesterday, 10 flew to New Zealand on the same flight - from India, via United Arab Emirates - over the weekend, on Saturday (March 27).

The eleventh person touched down on a flight from Italy, via Singapore, on Friday (March 26).

"Additional testing, including whole genome sequencing, will help indicate whether any of the cases are related," the Ministry said.

"Interviews, and where indicated, further testing will help to determine whether any of these cases are historical."

The statement said data showed that since the beginning of the year, at least one in eight Covid-19 cases are historical.

As of yesterday, the total number of cases in New Zealand stood at 86.

The total number of confirmed cases in New Zealand is 2137.

Since the start of this year, there have been 42 historical cases reported out of a total of 325 cases.

Authorities also said yesterday that the investigation into the Grand Mercure Auckland hotel cases continues.

A total of 236 of the 272 people officials were trying to get a hold of have been contacted as of 9am yesterday.

Of those, all except for one person had tested negative for coronavirus.

"One person has returned a positive result which is classified as a historical infection on the basis of further testing and serology results," the statement said.

"Historical cases are not considered to be infectious."

Queensland cluster grows overnight

Today's statement will come just as Queensland authorities have announced that its latest cluster has grown by 10 positive cases overnight.

The new community cases bring the cluster to 15 cases - including two men from the city's north, a nurse and her sister and two people believed to be colleagues of one of the northside men.

Brisbane residents started a three-day lockdown at 5pm yesterday, local time, after officials made the sudden announcement a few hours earlier when the new community cases were discovered.