A Wellington wedding, an Auckland school and a Hamilton rest home are among the suspected sources for clusters of coronavirus cases.
Clusters refer to an event or location linked to multiple confirmed or probable cases of coronavirus.
Today Ministry of Health Director-General Dr Ashley Bloomfield detailed multiple possible clusters under investigation.
Several confirmed cases have been linked to the World Hereford cattle conference in Queenstown, while 11 people have been diagnosed with Covid-19 from Auckland's Marist College.
Other clusters being investigated include a wedding in Wellington, a rest home in Hamilton, a trip to the US by a group of Wellington friends and a contact with the Ruby Princess cruise ship in Hawke's Bay.
Eleven staff and students have been diagnosed with the coronavirus at Auckland's Marist College.
In a video update today, the Board of Trustees acknowledged the concerns from family and community members.
"I give my word that we're doing everything we can to work with our authorities and to relay that information back as soon as we are able to," board chair Stephen Dallow says.
"Often we are hearing things the same time as the media, often it can feel delayed by the time we can get a message out through our system to our 800 families."
Seven of the confirmed cases are teachers and the other four are students.
Mr Dallow says they're expecting more cases to be confirmed in the coming days.
One confirmed case has been linked to the Ruby Princess' arrival in Hawke's Bay.
It docked at Napier port on March 15.
In a statement today, the Hawke's Bay District Council asked people who have Covid-19 symptoms and were in close contact with any Ruby Princess passengers to call their local GP.
Two other cases of the coronavirus were confirmed in Hawke's Bay today, both people returning from overseas travel.
There are now six confirmed cases in the region.
WORLD HEREFORD CATTLE CONFERENCE
Another one of the clusters is the World Hereford cattle conference, which was held in Queenstown between March 9-13.
It drew attendees from around the world, including Europe and the US.
So far at least four people have tested positive and others who attended are in self-isolation.
OTHER POTENTIAL CLUSTERS BEING INVESTIGATED
Health authorities are still investigating several other potential clusters, including cases linked to a wedding in Wellington and others to a rest home in Hamilton.
The majority of cases are from people returning from overseas, with all arrivals from last week onwards made to undergo a 14-day self-isolation.
There are also four cases being treated as community transmission - where no known link can be made to overseas travel or other confirmed cases.
Three of those cases are in Auckland and the fourth is in Wairarapa.