Director-General of Health Ashley Bloomfield says he is fully expecting there will have been new cases overnight, but he has not been advised of them yet.
Health authorities announced three new cases last night, taking the total number of active community cases to 10.
One of these cases is a woman in her 60s who is an Air New Zealand cabin crew member but who has no known links to the existing cluster and may have been infectious for more than two weeks.
Dr Bloomfield said the cut-off time for overnight reporting is 9am, and he expects to be briefed by his officials then.
"One of the things from the New South Wales outbreak is we've seen around 70 percent of the cases there have been are household contacts and there's been a lot of testing over the last day or two of those close contacts, particularly within households so fully expect there will be more cases overnight."
Bloomfield said the Covid positive Air New Zealand cabin crew worker was picked up through regular routine testing.
"Of course we'll be doing the whole genome sequencing, just as we do on all cases just to see if that fits with, or is part of the current outbreak - but it seems likely that that's a separate coincidental infection."
He said there has been a big increase in the number of locations of interest with around 70 now around Auckland and the Coromandel.
"The very important thing now is that people look at those, particularly people who are essential workers, because any essential worker who has been at a location of interest needs to stay at home and get tested."
Asked how one of the positive Covid-19 cases seem to go back to 3 August, Bloomfield said none of the sewage testing up until the middle of last week had any detections in the Auckland region.
"It may well be that one of the cases has described symptoms that go back a period of time, even though their test is only positive now, so this may be the Public Health Unit being inclusive around that particular report."
Bloomfield said health officials will be preparing a paper for Cabinet to consider tomorrow regarding the timing of the level 4 lockdown which is currently at least three days around the country and at least seven days in Auckland and Coromandel.
"Our aim of course would be to have as short as possible lockdown but it's so important in this situation, we've seen that from the different outcomes in different states in Australia, that ... you go into lockdown type arrangements quickly and you don't lift them too early."
Bloomfield said they will be looking for good testing rates right around the country and so far all the 10 reported cases have been in Auckland and they are all related, aside from the cabin crew member, as well as looking at the results of wastewater testing which is being done right across New Zealand.
"That will inform the advice and Cabinet's decision and it will be that there could be a different decision for the South Island and we'll put up advice around that."
Bloomfield said he expects they could be able to get back up to the 50,000 vaccines a day despite extra safety measures being necessary due to being in alert level 4.
This is an official COVID-19 ALERT.
All of New Zealand is now at Covid-19 alert level 4.
The alert level will be reviewed after 3 days for all areas EXCEPT Auckland & Coromandel Peninsula which is likely to remain at level 4 for an initial period of 7 days.
A community case of Covid-19 has been identified.
Stay at home where possible & follow the Alert Level 4 guidelines. This will stop the spread of COVID-19 and SAVE LIVES.
Everyone is asked to:
Wear a mask and keep a 2 metre distance from others whenever you leave your home.
If you are sick, call your doctor or Healthline on 0800 358 5453 for advice about getting tested.
Keep on scanning QR codes whenever you leave your home.
Practice good hygiene - wash hands often.
Services including supermarkets, pharmacies, clinics & petrol stations will stay open at Alert Level 4. Face coverings are mandatory for all people - both employees and customers - at businesses and services operating at Alert Level 4 involving customer contact.
For more information on Alert Level 4 go to [the government website www.covid19.govt.nz]
RNZ is the statutory Lifeline Utility responsible for radio broadcasting under the Emergency Management Act 2002 and it has a memorandum of understanding with Government which has been activated to help deal with potential health issues related to the pandemic. RNZ's Lifeline Utility obligations do not affect our editorial independence as a public media organisation or the rigour of our news gathering and reporting operations.
As New Zealand's Lifeline Utility radio broadcaster, RNZ is required to maintain essential public information channels and news during times of national emergency and we are committed to supporting all New Zealanders.
We are also committed to looking after the health and well-being of our staff.
RNZ will continue to provide essential information services - broadcasting and publishing critical public service announcements on air, on our website and via social media channels. Comprehensive news will be available on air and via our website and digital services.
If necessary RNZ Concert and RNZ Pacific will carry news and information from RNZ National. Parliament will continue to be broadcast on the AM network when the House is sitting. As the country's public service media organisation, RNZ is committed to supporting all New Zealanders.
Kia Kaha - Stay Strong