Testing has found two new cases of Covid-19 in people in managed isolation and quarantine (MIQ) facilities, and no new community cases, the Ministry of Health says.
In a written statement, the ministry said the two new cases arrived on the same flight as 10 cases detected yesterday, which travelled from India via UAE.
"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 ministry said.
"They may have been incubating the virus at the time or be exposed to the virus after being tested."
The National Party has been pushing for pre-departure testing to be tightened up, saying only Immigration New Zealand approved laboratories should be able to provide such tests.
The ministry said it did not consider the cases from India as entirely unexpected, given the country was reporting the highest number of daily Covid-19 cases worldwide.
"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."
The ministry said its investigation into the Day 12 case at the Grand Mercure facility was continuing.
"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 ministry said.
Some 28 people had not yet returned results.
The Day 12 case involved a person who received a positive Covid-19 test while on an exercise trip, having taken a bus to a separate location. They then bussed back to the facility with 14 other returnees.
A second person who was staying on another floor subsequently tested positive for the virus, with genome testing showing the infections were related.
The ministry said the extra precautions taken over the case were ended yesterday, due to reduced risks.
Eight recoveries in the past day brings active infections in New Zealand to 80, with total confirmed cases at 2139.
The rolling seven-day average of new cases at the border was four.
Laboratories processed 3722 tests yesterday, for a seven-day rolling average of 5070.
Other developments today
A Cybersecurity expert told First Up today that his company's scanning of the Dark Web had picked up discussions about fake Covid-19 test results on New Zealand forums, and the forged certification was easy to find in the covert area of the internet.
Epidemiologist Michael Baker said too many people with the virus were coming into the country, which showed that the pre-departure checks needed to be tightened.
He said better auditing of the certification was needed, and travellers should be asked to provide more information about where they were tested, in their communication with MIQ before they arrived.
Yesterday the Ministry said there were 11 new cases of the people diagnosed with the virus, all in MIQ. All but one of them arrived from India via the United Arab Emirates on Saturday.