Genome testing of the latest batch of infections has confirmed it is a new strain, authorities said, probably from Australia or Britain.
New Zealand has recorded new cases of community transmission of COVID-19 for the first time in more than 100 days.
It is one of the places the UK Government has announced that English holidaymakers can visit without having to self-isolate on their return.
The New Zealand prime minister said the Queen wanted to have a catch up and see how everyone in the country was getting on.
A suppression order under New Zealand law means the man who killed backpacker Grace Millane can't be named despite being jailed for life.
Stephanie Simpson, 32, went missing after going for a hike on Saturday at Mount Aspiring national park on New Zealand's South Island.
Police said the number of people missing after the volcano erupted on Monday is in double figures.
A court heard Grace Millane had profiles on BDSM dating apps and had allowed a former partner to choke her during sex.
Brenton Tarrant, 28, pleaded not guilty to 51 counts of murder, 40 counts of attempted murder and one terror charge relating to the March mosque attacks in Christchurch.
New Zealand’s prime minister Jacinda Ahern has written to an 11-year-old girl explaining that she couldn’t accept a “bribe” of $5 to conduct research into dragons. The girl, identified only as Victoria, had written to the prime minister to say that she wanted to be given telekinetic powers so that she could train dragons, and included the money with her letter. In a personally signed letter with the official letterhead of the New Zealand premiership, Ms Ahern thanked Victoria for getting in touch but had to dash her hopes around dragons.
Jacinda Ardern’s announcement comes less than a week after 50 people were killed in the attacks.
A suspected gunman broadcast live footage on Facebook of the attack on one mosque in the city of Christchurch.