The fate of those who breached lockdown and isolation rules, plunging Auckland back into lockdown, now sits squarely in the lap of director general of health Dr Ashley Bloomfield.

But Bloomfield has indicated he won't ask the police to take action over the Covid breaches.

Meanwhile, Bloomfield says there were no new community cases overnight.

Bloomfield told Newstalk ZB's Mike Hosking he was looking for zero days of community cases to determine when lockdown should come to an end and the alert level lowered.

He said one of the cases which sparked Auckland's lockdown had been about for a week while infectious and that was a key reason why the alert level was raised.

He said he wasn't getting the police involved so far this lockdown because the families needed support to navigate isolation.

On not getting police involved at the outset, Bloomfield said: "In the first instance we get our health providers to go out because often what it is the families just need support to stay isolated safely. If we have any issues or challenges or if we can't find people then we don't hesitate to involve the police."

He said he spoke to the Police Commissioner yesterday who told him they are "willing and ready and standing by as they need to".

He said in this outbreak close contacts were being called daily and if no one was at home, health officials would then involve the police.

He said he did not think a punitive approach was the best way to counter the virus and get people on board.

Bloomfield imagined the MIT student that sparked this lockdown "wasn't having a great time" at the moment.

"I imagine he's extremely remorseful at the moment. It's a pretty heavy burden to bear," he said.

Bloomfield said with the current cluster with 15 cases and high infection rates in families, the positive tests from casual exposure was a concern in this outbreak.

Bloomfield said it was difficult to cordon off a community in this outbreak, unlike what happened in Sydney during a recent outbreak.

He revealed officials discovered the connection between the two families on Sunday morning

"It really helped our investigation to enlist that information early. It was volunteered early and that's actually really helpful with what next steps we take."