Health Minister Chris Hipkins says it still not known how a family of four contracted Covid-19.

There are 13 new Covid cases in the South Auckland cluster, all linked to the original four confirmed cases from the new outbreak first confirmed on Tuesday.

The new cases include children. One is a girl aged 1-4 while the other is a boy aged 5-9. Another girl who tested positive is aged 10-14, while a teenage male (aged 15-19) is among the new cases.

Hipkins told Heather du Plessis-Allan the goal was to still identify how the family contracted the virus.

"That's the goal - how the family got it in the first place. It is a cluster; we haven't seen any cases outside the cluster.

"They are either in quarantine or on the way to quarantine. I can tell you they have been required to go to quarantine."

He revealed the cases announced today would be in the Jet Park facility by the end of the day.

The original four family members are all in quarantine.

Details about the rest-home in Matamata would be released shortly after a positive Covid person visited over the weekend, he said.

"There are a lot of rumours flying around at the moment. Everyone (at the rest home) who need to have been tested have been tested."

He refused to say if any were showing signs of symptoms, saying this would be released tomorrow.

He said pop-up testing stations had been launched, with staff from hospitals, to try to cope with the workload.

"That's pretty rapid ... in less than 48 hours now."

He acknowledged officials would have liked to have set up road blocks earlier than they were.

"It is not feasible to build a wall at either end of Auckland."

Officials were looking to trial a Covid card, but it was not considered a silver bullet.

"The Covid card would not stop the need for a lockdown necessarily."