The Minister for Pacific Peoples says some people sick with Covid-19 have never engaged with the health system before.
Aupito William Sio, who is also an Associate Minister of Health, told Morning Report there is a group in society who aren't speaking up until it's too late.
"What we're seeing is , and I use this sparingly for lack of a better word, the underbelly of our communities, people who are not necessarily engaged with our health system, have never engaged with our health system until it's usually too late.
"Therefore, what's happening is it's really important for our government agencies, to be working closely with our providers, both Māori, both Pacific, and generally, people who are known to the local communities, who have a long standing relationship and a trusting relationship with people so that they can step forward."
Sio said some people may also be nervous about getting tested if they are the breadwinner, or sole family caregiver.
He also said the government believes it does have the current delta variant outbreak in Auckland under control.
"What we're seeing is the way that delta behaves. It's much more infectious, more aggressive, and so we're seeing the tail end of the original outbreak cases.
"The officials are giving us a great deal of confidence that if everybody plays their part, and we're continuing the testing in suburbs of interest, that we're heading in the right direction."