One case from South Africa has tested positive on day 18, said the Ministry of Health in a statement. That person was in a travel bubble of a previously confirmed case reported on December 31.
The traveller arrived from South Africa via the United Arab Emirates on December 26 and has been in Auckland's Jet Park quarantine facility since the contact case was first detected.
The other cases come from all over the world including the US, Malaysia, India, South Africa, Italy, United Kingdom, Russia, Bahrain, and the United Arab Emirates.
Two more international mariners who arrived in Christchurch on January 6 have tested positive.
The Health Ministry said there were now 19 positive Covid cases identified in this group with nine deemed historical and 10 active.
Meanwhile, people from the Cook Islands will be allowed to come to New Zealand without going into quarantine from next week.
"Following confirmation of the Cook Islands' Covid-free status, and the implementation of strict health and border protocols we are now in the position to resume quarantine-free travel for passengers from the Cook Islands into New Zealand," Prime Minister Jacinda Ardern said.
Cook Islands Prime Minister Mark Brown said Cook Islanders needed to access essential services here.
Strict protocols will be in place including pre-departure health requirements and separation from other travellers at Auckland International Airport, to prevent the risk of Covid spread from travellers from other countries, Ardern said.
The announcement does not change the criteria for entry into the Cook Islands which is limited to Cook Islanders and current holders of Cook Islands work and residence permits who meet Cook Islands health entry requirements.
But Ardern said work was ongoing to allow two-way quarantine free travel between the two countries "within the first quarter of 2021".
It comes as tough new travel regulations come into force later today for Kiwis returning from global covid hotspots as concerns mount over New Zealand's vulnerability to the most contagious strains to date.
With 62 active cases in managed isolation, including cases linked to the infectious variants circulating in South Africa and the United Kingdom, there are renewed calls by our top health official and scientists to not get complacent as we enjoy a summer break that is proving the envy of the world.
There are presently no cases in the community.
In the most recent cases a group of international mariners who arrived from Russia on January 6 have seen infection numbers at the border rise sharply. So far 17 seamen have tested positive with nine deemed historical and eight active.
To help strengthen the country's health defences strict pre-flight Covid testing is set to come into force at 11.59pm tonight.
All travellers from the United Kingdom and the United States who are landing in New Zealand will need to have a negative Covid-19 test result before departure.
The latest requirement means before flying travellers will need to have had both a covid sample taken and the result returned no more than 72 hours before the scheduled time of the first international departure.
A positive test results in an automatic ban from travelling until a test comes back negative and a medical certificate confirms recovery.
Last week covid response minister Chris Hipkins signalled this would be extended to more countries as the outbreak worsened.
Those travellers from Australia, Antarctica and some Pacific Islands would remain exempt.
Meanwhile, top scientists are warning the new variants of the virus had to the potential to spread like wildfire.
Calls are being issued for everyone working in managed isolation quality to be on full alert, and the public to use the Covid Tracer App and switch on the Bluetooth function.
Data has revealed the number of daily scans on the tracer app has plummeted from its peak of 2.5 million in September to around 500,000 in recent weeks.
There's also been a drop off in the number of tests, with 2187 processed on Monday and 4847 tests processed on Tuesday. The most recent seven-day rolling average was 3729 tests.
Public health expert Professor Nick Wilson said the scanning numbers were "problematic" and would make reacting to a community outbreak difficult.
Earlier director-general of health Dr Ashley Bloomfield warned that Kiwis could not afford to get complacent when it came to using the app.
"We've seen how quickly the virus can spread," he said.
"We all have a responsibility to support contact tracing by keeping a record of our movements, either with the app or by another method such as a diary.
"When someone tests positive for Covid-19, the faster they can provide contact tracers with information about where they've been, the faster contact tracers can get ahead of the virus and break the chain of transmission."
