Director general of health Dr Ashley Bloomfield has revealed that some cases in the five-week Delta outbreak came as a result of transmission between households.
Speaking to the AM Show this morning, Bloomfield admitted there "clearly has been some interaction between households that has led to some of these new cases".
"I dare say that wouldn't be unique," Bloomfield said.
Defending level 3 as "very strict", Bloomfield said that authorities still expected dozens more cases to emerge despite shifting down alert levels at midnight yesterday.
"We know Delta spreads quite liberally inside households. These are household members or very close contacts, who are now isolating and we just know from the sort of conversion rate somewhere between 10 and 20 per cent, that over the next couple of weeks about 50 or 60 of them are likely to come through."
In yesterday's 1pm briefing it was revealed that of Monday's five unlinked cases, four were geographically close to other households where there are cases.
Aucklanders today embraced fresh coffee and fast food as they welcomed life in level 3.
After five long weeks of restrictive alert level 4 lockdown, residents of our biggest city today emerged to new relative freedoms of takeout coffee, takeaway food and contactless shopping.
But Bloomfield admits he lost sleep over the decision to move alert level as an expert warns that dropping alert levels now is dangerous, and any wrong move could see cases explode and Auckland plunged back into level 4 lockdown.
Bloomfield says the country might not return to zero Covid cases - but that won't necessarily stop a return to level 1.
Asked if there were any reservations about moving Auckland out of level 4, Bloomfield told the Breakfast show these decisions were not always straightforward.
The advice he gave to Cabinet was based on all the data and advice passed on to him by health officials and medical experts.
The advice was that it was safe and it was time for Auckland to move down to level 3.
Covid-19 modeller Shaun Hendy told TVNZ the country could still eliminate the virus while in level 3.
"Definitely - it's going to require us to play our part."
Hendy said two weeks could just be enough for us to "wrap this cluster up".
The worst-case scenario would be for the cluster to grow and develop into high numbers during level 3.
He warned that could lead to officials moving Auckland back up to level 4.
Hendy said the number of unlinked cases starting to drop was a positive sign.
It was also fantastic to see the high number of people turning out to get vaccinated, he said.