Director general of health Ashley Bloomfield says New Zealand has no new Covid-19 cases.
There were 6273 tests completed yesterday and a total of 327,460 total tests.
"It is very reassuring that we have no further cases of Covid-19 to report," Bloomfield said.
This was especially the case given the increase in testing numbers.
Bloomfield said more than 19,000 people had been in a managed isolation placement.
Two further clusters have been closed - the Bluff wedding cluster linked to 98 cases and the Rosewood rest home cluster linked to 56 cases and 12 deaths.
That meant only one cluster remained open.
The key approach to managed isolation was keeping people isolated for 14 days.
Now the routine testing had been added to that, he said.
New Zealand has three active cases of Covid-19.
Yesterday, a man in quarantine at the border tested positive for Covid-19 after arriving from Pakistan via Doha and Melbourne on June 13 on Air NZ flight 124.
Three people on the flight with him who were granted compassionate exemptions to leave managed isolation are being chased up for tests, Bloomfield said.
However, two of those people had already returned to managed self isolation because they were only given one day compassionate exemptions to leave the facility.
Also this week, it was revealed two sisters who arrived from the UK to see their dying mother had tested positive for the virus - ending New Zealand's 24-day streak of no active cases.
They were granted permission to drive to Wellington from Auckland despite not having been tested. It was later revealed they became lost and were met by friends.
Follow-up tests
Bloomfield said the 401 people considered potential contacts of the two women were being tested.
Bloomfield said all those who had been given passes out of managed isolation on compassionate grounds were being called back to receive Covid-19 tests.
Since the beginning of April, there have been 37 positive cases of Covid-19 based on tests of only those who showed symptoms.
Only three of those cases were in recent days since mandatory testing of people arriving in New Zealand from overseas.
Bloomfield said authorities now had the power to hold a person up to 28 days if they refuse a Covid-19 test.
He said the 6273 tests conducted yesterday enabled health officials to be sure they were ring fencing possible infections from the two women.
And the current return of negative results gave authorities growing confidence there was not widespread community infection.
Bloomfield said health officials were first chasing up and testing everyone deemed contacts of New Zealand's three recent cases.
Then they were working back to count how many people had been let out of managed isolation without tests.
However, he said all those people would have completed their 14 days isolation.
In managed isolation, 700 people will be tested today.
New arrivals
Bloomfield said people arriving in New Zealand were not compelled to take a Covid-19 test.
However, it was being made clear to them that they could not leave a managed isolation facility earlier than 14 days if they were not first tested.
They could also be compelled to stay another 14 days on top of the initial 14 days if they refuse to take a test and health authorities have concerns.
Bloomfield said he had taken responsibility for not putting all the appropriate processes in place to keep New Zealand safe.
There was no longer any confusion about testing. Since Tuesday he had made it clear no one would leave a managed isolation facility before 14 days without a negative Covid-19 test result.
When asked if the ministry could put a number to the amount of people that have left an isolation facility without a test, Bloomfield said he could not yet do so.
New flight rules
Yesterday Bloomfield said the Ministry of Health would now require passengers to wear masks on flights from Australia.
This was because many people flew through Australia from other countries and all of the three latest cases had come via Australia.
And Air New Zealand crew flying long-haul international flights, such as to the United States, are now required to self-isolate at home and return negative tests before being allowed into the community.
Air crew on other long-haul international flights already have "very strict" protocols in place, including not going "land-side", said Bloomfield.
Concerning flight
Former RNZ reporter Alexa Cook is in quarantine at the Novotel Auckland Airport, having arrived from the UK and was on the same flight as the man who tested positive yesterday, a week ago.
She said at the time there was no social distancing or masks and that concerned her.
"We were sat in the middle of a row of four people - we had people right up against us," she told RNZ.
"Masks were not compulsory, the flight attendants were only wearing a mask and no other PPE ... and the flight itself seemed to be very crammed, very busy."
