It appeared the outbreak could be clearly linked to Americold in the first instance - and that this gave investigators the best lead. He said it may eventually prove to have no link, but an Americold worker had the earliest symptoms.
Three people are in hospital. One is in Middlemore. Two are in Auckland.
To date, 66 people linked to the cluster have been moved into quarantine.
The person in isolation is a child who arrived from Afghanistan and is in managed isolation at the Pullman Hotel.
New Zealand now has 1271 Covid-19 cases. Of the 49 cases in the community outbreak, all but three are linked.
There have been 1536 close contacts of the cluster identified by the contact tracing centre. All are self isolating.
Bloomfield said the response was "tremendous". He urged people who were called by the contact tracing team to take the call - or return it if they missed it.
Officials were working closely with two religious organisations to help with contract tracing.
Bloomfield said he wanted to thank people who were getting tested. He knows there are still some long waits.
"To those who are waiting very patiently, thank you very much."
'Vile slurs ... totally wrong': Beware social media
Health Minister Chris Hipkins issued a stern warning about social media, saying sharing of unverified information had created "extreme distress" for the family at the centre of the current cluster.
He said one post in particular contained a "number of vile slurs and was totally and utterly wrong".
"At a time we are fighting a pandemic, this sort of behaviour is designed to create panic ... and is completely unacceptable," he said.
He made a plea to New Zealanders to be careful about what the believed and shared, and said information sourced on social media could not be treated as official.
Hipkins said there have always been rumours but this smacked of orchestration.
He begged people to think twice before sharing unverified "nonsense".
"Please take your information from official sources," he said.
"The information here is verified, the information that we share during these press conferences ... is information that you can trust. If a mistake is made, it is quickly corrected."
Hipkins said the Government was working "really hard" to make sure trusted information was being released.
Hipkins said the social media rumours had been pushed hard and his message to people doing so was "stop doing that".
"My plea to New Zealanders is please be responsible and sensible about what you share on Facebook."
Addressing who was pushing the rumours, Hipkins said: "It's clear there are people out there who are pushing it hard and my message to them is stop doing it."
He wanted people to take personal responsibility for the information they were passing on.
He called on all leaders - including politicians - to take responsibility for the information they shared.
But he said "it may be that we don't find the exact point of transmission".
Bloomfield said "almost all" of the close contacts of those with Covid had been tested.
Unprecedented testing
Hipkins said testing levels were "unprecedented" and 23,682 tests were processed yesterday, with 63,231 processed across the last three days - which was an "exceptional effort".
He said the system was working at "top speed" and "that should give us confidence".
Processing was being slowed down though due to the huge volume of testing.
"Positive results are reported first and promptly," said Hipkins.
Hipkins reminded the public that travel out of Auckland was still restricted. Only those with an exemption can leave or enter Auckland.
Hipkins confirmed the official QR code should be able to be used in apps different to the Government app.
He encouraged people to use the official app - but work was being done behind the scenes to ensure that whatever app was used, the code could be scanned and movements tracked.
People not using phones should be keeping track of their movement in other ways - as should businesses.
"They need something for people who are not using the QR code," Hipkins said.
Tauranga testing
Bloomfield said there will be a mobile testing unit available at the Port of Tauranga from tomorrow.
Bloomfield said the Tauranga mobile testing station would have eight nurses, admin and IT support.
They would test through the week for as long as they needed to. The priority would be port workers likely to have had contact with crews from trips.
On masks
Hipkins said he wanted to make sure people could access a mask.
Supermarkets were working to ensure they had good stocks.
"We could make it compulsory ... what we need is a cultural acceptance. If we're asking you to wear a mask, there is a reason."
He said the Government could spend a lot of time and money on making masks mandatory but he preferred to have a social shift and ensure everyone knew how important it was to wear masks where they could.
Hipkins said, at level 3, people should minimise their movements.
If you were not going to work you should be staying home, he said.
"People shouldn't just be out and about taking a day trip to Waiheke," he said.
Hipkins said police could take action against people not adhering to level 3 restrictions.
He said as at 4pm yesterday, 50,468 vehicles had been stopped at Auckland's borders, of which 676 were turned back. Of those, 428 were seeking to leave Auckland - the rest trying to get in.
Hipkins said anyone not clear on level 3 rules should visit the official website.
In general "minimise the amount of movement you have ... if you don't need to come into contact with someone, just stay home," Hipkins said.
He said New Zealanders should already be "reasonably familiar" with the rules.
"Just think about minimising risk ... let's just all do what we can to stop the spreading of the virus," he said.
The election
When asked about the election, Hipkins said the matter was ultimately up to the Prime Minister.
He said neither he or Bloomfield would comment before the PM had announced her decision.
Bloomfield, when pressed, said he had already advised the Electoral Commission on health risks associated with voters turning up en masse to cast votes.