Dr Ashley Bloomfield is pleading for people to follow the rules of ongoing lockdowns in Auckland, Northland and Waikato.
Waikato and Northland will remain at Level Three until at least Thursday, while Auckland will remain under its current restrictions for at least another week.
The Director-General of Health says officials are expecting to identify several locations of interest, after Police last night located the Northland case's travelling companion at a West Auckland address.
He says many staff and patients of a new Covid-19 case at Auckland's Middlemore Hospital are also being identified.
Bloomfield told Mike Hosking his message to people is simple.
"We've got to maintain our effort here to control the virus, keep the numbers as low as possible in Auckland and keep getting those vaccinations up, and the number is 90 percent, and it's got to be right across the community."