There are no new Covid-19 cases in the community after a testing blitz that saw more than 6000 people swabbed yesterday.

Over the last seven days, there has been about 38,000 tests, which Covid-19 Response Minister Chris Hipkins said helped provide "invaluable information" to rule out community transmission.

The level of community testing with no new cases provided reassurance for Aucklanders wanting to go away for the long weekend as long as they followed the general public health advice to use the Covid Tracer app and stay home and get a test if you're sick, said Hipkins.

"There is no reason why people's travel plans should change," he said.

The preliminary results of the ESR investigation into the Pullman Hotel - presently linked to three community cases - will be available at the earliest this evening with more detailed scientific advice expected at the end of next week.

There are potentially two more additional cases at the hotel, Hipkins said.

From tomorrow, all returnees will need to stay in their rooms at MIQ facilities after their day 12 tests and prior to their departure.

After five hectic days of testing across Northland and Auckland health authorities scrambled to find evidence the virus has spread in communities.

So far all positive cases, a 56-year-old Northland woman and an Orewa man in his 40s and his preschooler daughter, have been scientifically linked with a fellow returnee staying in managed isolation at Auckland's Pullman hotel managed isolation facility.

A mother has also claimed that her teen daughter was infected at the Pullman after travelling from South Africa.

Results from six of 11 close contacts of the father and daughter are also expected back today. Five results had come back negative, with everyone affected isolating for a fortnight.

Genome testing has revealed all infected returnees had the same highly contagious South African strain detected in a teenage girl who stayed at the central city isolation facility at the same time.

The Pullman Hotel remains under the microscope as officials investigate how the virus spread between returnees during their mandatory two-week stint in isolation.

It has been revealed swipe card data show periods when all three cases were out of their rooms and in common areas of the hotel at the same time.

The facility is now closed to new arrivals and once all those currently isolating have left, it will undergo a hospital-grade "deep clean".

As well as this, all returnees across all managed isolation facilities will now be required to stay in their rooms for the last two days of their time in quarantine.

The Government is also investigating "extra requirements" for those leaving MIQ facilities.

Health authorities are now awaiting results from the remaining 48 of 353 returnees that stayed at Auckland's Pullman hotel between January 9-13, at the same time as those who were infected.

Yesterday the Australian Government announced 12 people were now in their country after staying in managed isolation at the Pullman during the infection period.

Nearly 20 locations of interest have been identified on Auckland's North Shore and Hibiscus Coast, including supermarkets, a mall department store and a restaurant.

Hundreds of concerned people are continuing to swamp testing stations across the region, with 14,105 tests carried out in Auckland between Sunday and 3pm yesterday.

Despite this, Hipkins said the region was "not seeing any evidence of community transmission at this point".