Aucklanders are back in lockdown for a full week and the rest of New Zealand is at level 2 after a person with Covid-19 visited public locations while symptomatic.

The 21-year-old man and his mother tested positive yesterday. Another member of their family is a student at Papatoetoe High School - but they've tested negative three times.

When the alert level change was announced last night, Director-General of Health Dr Ashley Bloomfield said he expected a link to other cases.

This morning, Deputy Prime Minister Grant Robertson told Francesca Rudkin early indications are that is exactly the case.

"Most closely linked to the second of the families that emerged over the last 14 days, so that's somewhat reassuring to us."

Covid-19 Response Minister Chris Hipkins told TVNZ''s Q&A that it was the UK variant, but he said officials have not yet confirmed how the new community case got the virus.

He said officials cannot yet confirm if other people have been infected. Hipkins is calling on anyone who has Covid symptoms to "go get a test now".

He is denying that Auckland came out of the lockdown too soon. At the time, things were looking contained.

The issue today is that a "seemingly unrelated person" to the current cluster has contracted Covid-19, Hipkins said. "We don't have all the information we need."

He said he learned about this new case in the early afternoon yesterday. After that, officials were looking to find much more information.

• Auckland moving back to Alert Level 3 - what does that mean?
• Alert level changes: Grant Robertson confirms business support packages

The new case - "Case M" - is a 21-year-old student who attends the Manukau Institute of Technology (MIT) and is the older brother of a Papatoetoe High School student. The man, who also works at Kerry Logistics (Oceania) Limited, went to MIT for three days and to the gym twice - including once after taking a Covid test - when he should have been isolating at home.

At a hastily arranged press conference last night, Prime Minister Jacinda Ardern announced Auckland would move into lockdown at 6am from Sunday and the rest of the country to alert level 2.

Major events have been disrupted. Sunday morning's Round the Bays run in Auckland was called off while the Black Caps' and White Ferns' T20 cricket double-header, scheduled for Eden Park on Friday, has been moved to Wellington where the games will be played without crowds. The racing schedule for the America's Cup - which was due to start on the Hauraki Gulf on Saturday - is being reviewed.

Ardern and director general of health Ashely Bloomfield made the announcement of alert-level changes after an urgent Cabinet meeting.

"This will take some time," she said, but at this stage, it was likely Auckland would stay at level 3 for the whole seven days. For the rest of the county, the level 2 settings will be reviewed throughout the week.

Ardern said the Government had no choice but to put Auckland back into lockdown after the new case was detected in the community.

Instead of following health advice, Case M had been out in the community while infectious. This included attending the Manukau Institute of Technology for three days - February 22, 25 and 26.

All MIT students were emailed on Saturday evening - they need to stay at home under the rules of level 3 and those considered close contacts will be followed up by health officials.

Case M is the older brother of a student from Papatoetoe High School who had returned three negative tests and was asymptomatic. It was announced last night that Case M's mother had also tested positive.

Ardern said there was "no doubt" that a contributing factor to the lockdown was that rules were not being followed.

The new community case should have been in isolation, she said. But after going to the GP to get a Covid-19 test, he ignored health advice and went to the gym.

He had also been to a number of other locations when he was symptomatic.

"Of course it's frustrating," Ardern said.

And she was leaving no room for interpretation when it comes to how clear officials made this to the new community case.

"I've seen the records of the multiple communications that went to members of the school community, advising them of what was required of students and household contacts."

The person visited:
• City Fitness, Hunter Plaza, Papatoetoe (February 26, from 3.20pm to 4.40pm, and February 20, from 12.20pm to 1.45pm)
• Manukau Institute of Technology (MIT) (February 22, 25, 26 - specific times yet to be released)
• Hunter Plaza (February 26, from 2.55pm to 5pm)
• Burger King Highland Park (February 25, from 8pm-9pm)
• Your Health Pharmacy (February 23, from 2.45pm to 3.50pm)
• Pak n Save Manukau (February 21 from 5.30pm to 6.40pm)

The Ministry of Health is advising people who were at the gym at the days and times above to: "Please stay at home, get tested as soon as possible and call Healthline on 0800 3585453. Remain at home until you receive a negative test result. Self-monitor for Covid-19 symptoms for 14 days from your exposure. If symptoms develop after your first negative result, get another test immediately and stay at home until a negative test result is received."

People at the other locations are being told to self-monitor for Covid-19 symptoms for 14 days. "If symptoms develop, get tested and stay at home until a negative test result is received."

Ardern sounded a warning to any would-be rule breakers. "We do have the ability to take enforcement action."

The action comes in the form of section 70 of the health order, which means a medical officer of health can oblige people to isolate.

But it was clear Ardern did not favour this heavy-handed approach.

"I don't want to create an environment where an individual who has made mistakes here, is so pilloried, that no one wants to be tested."

She urged everyone to "please follow the rules on behalf of everyone".

Police have today again set up roadblocks at the Auckland region borders. "The checkpoints on the outskirts of Auckland will be stopping vehicles and questioning drivers, ensuring there is no non-essential movement through the region," a police statement said. "Anyone attempting to travel across the regional boundaries should expect to be stopped and asked for proof of essential travel."

But National leader Judith Collins wants the Government to throw the book at people who ignore the rules.

"We need to consider tougher penalties against those who are not following public health advice around isolation and testing," she said.

She added that all New Zealanders would be frustrated at the level of non-compliance of the person at the centre of the new developments.

"Relying on people to do the right thing looks to have reached its limits and we may need tougher penalties to make sure everyone follows the rules.

"No one wants to be yo-yoing in and out lockdown."

Ardern said Cabinet considered a numer of factors when looking at the new case and deciding if another lockdown was needed.

The exposure the new cases had with others worried Ardern the most.

"Because they have been infectious for as long as a week and had not been in isolation, there are a number of high-risk places involved in this case."

Given the time that has passed since the onset of their illness, Ardern said close contacts might already be infected.

The lockdown, Ardern said, would help prevent a large-scale spread.

It was Cabinet's "unfortunate, but necessary position of needing to protect Aucklanders once again".

As Auckland will be at level 3 for a week, any affected business can apply for the wage subsidy and the business support scheme.

Any business in the country that takes at least a 30 per cent hit as a result of the lockdown can claim these subsidies.

Finance Minister Grant Robertson said rough $400-$500 million had been budgeted for these schemes.

Ardern said the seven-day lockdown was needed as it was the same amount of time the new case was infectious in the community.

She said it must be assumed that the strain of Covid-19 is the more infectious variant. "The main thing we are asking people in Auckland to do is to stay at home."

This would reduce the risk of the virus spreading, she said.

When they can, people should work from home and children should stay home from school.

But, as was the case in previous lockdowns, supermarkets and pharmacies will remain open during level 3.

"Please, again, there is no need to rush to your supermarket."

Ardern said all sports or any other sorts of events need to be cancelled.

And the Auckland border will be reestablished – this will prevent anyone who does not have clearance from leaving the city.

Bloomfield last night also revealed that after testing the rest of the new community case's household contacts, the case's mother had tested positive for Covid-19.

When speaking to media last night, Ardern said some people may ask if Auckland should have remained at level 3 and not come out of lockdown.

But she said this was not the advice that the Government was given.

She pointed out that there had been 118,000 tests since February 14, when the first case of the new cluster was revealed.

Auckland Mayor Phil Goff said he understood Aucklanders' frustration at having to return to level 3 lockdown.

"However, the consequences of letting the virus spread would be far more disruptive and would put people's lives at risk.

"Aucklanders are old hands at this now. We know what to do to beat the virus and we will get on and do it."

How Kiwis reacted to the news

Boos greeted the alert level announcement at the Joseph Parker v Junior Fa fight at Spark Arena in Auckland - but cheers erupted when the crowd was told the boxing was allowed to continue.

The announcer told the crowd the news, but then said: "But hey! We're gonna have these fights!"

Support for business

Finance Minister Grant Robertson said that since the lockdown was scheduled to be for seven days, business support now kicked in.

This timeframe triggers the wage subsidy scheme and this applies nationwide. This would be paid in a lump sump, he said.

He said businesses could receive both the wage subsidy scheme and the new alert level 2 subsidy scheme.

He said the Ministry of Social Development had been providing support to the Papatoetoe area.

He is asking anyone in the area who needs to, to get in contact with MSD.

He said there were some families where a disruption like this would cause them "significant concern".

The Government has budgeted $400-$500 million for the coming seven days.

On the costs, he said: "We have this buffer available".

Robertson said the worst thing for the county and the economy right now would be a massive Covid-19 outbreak.

Based on previous lockdowns, Auckland level 3 and the rest of NZ at level 2 cost the economy about $440 million a week, according to ASB.

Case L - KFC

KFC Botany was closed for deep cleaning on Friday after a staff member - linked to the current Covid-19 community cases - tested positive.

The staff member was called Case L and is linked to the latest string of cases.

The person worked at KFC Botany Downs between 3.30pm on Monday, February 22 and 12.30am on Tuesday, February 23.

Members of the public who entered the store between those times are close contacts and should isolate at home for the remainder of the 14-day period, until March 8.

They should be tested on day 5 and day 12.

Members of the public who went through the KFC drive through between 3.30pm on Monday, February 22 and 12.30am on Tuesday, February 23 are casual plus contacts and should isolate at home until a negative day 5 test result is returned.

Judith Collins on the lockdown

The new lockdown in Auckland and Level 2 for the rest of the country will be disappointing for all, National leader Judith Collins said.

"No one wants to be yo-yoing in and out lockdown.

"National said the decision to go out of Level 3 on February 17 was a bold and ambitious call.

"At the time we still didn't know the source of the original case, there were two new community cases of the more transmissible strain that day, and not all of the high school students had been tested.

"Now Auckland is back in lockdown with all the consequences that brings. We need to consider tougher penalties against those who are not following public health advice around isolation and testing.

"All New Zealanders will be frustrated at the level of non-compliance. Relying on people to do the right thing looks to have reached its limits and we may need tougher penalties to make sure everyone follows the rules.

Auckland mayor's message to Auckland

"I understand Aucklanders' frustration at having to return to Level 3 lockdown, with the disruption it causes to everyone's lives and the impact it has on businesses, many of which are already struggling," Auckland Mayor Phil Goff said.

"However, the consequences of letting the virus spread would be far more disruptive and would put people's lives at risk.

"No one wants to be in lockdown, but it is the most effective means by which to stop a potential new outbreak, especially given the increased transmissibility of the new variant of the disease," he said.

"We are in a much better place than almost any other country in the world because of our strong collective response so far, so we need to keep it up.

"Aucklanders are old hands at this now. We know what to do to beat the virus and we will get on and do it."

Health officials' focus remains on KFC in the Auckland suburb of Botany. A family member of one of the Papatoetoe High School students who tested positive had been told to stay home and isolate, but instead went to work at the fast-food restaurant on Monday.

The Ministry of Health said earlier on Saturday there were three categories of contacts related to KFC. Eleven people in the first category are close contacts plus who also worked there and are in 14-day isolation.

Members of the public who entered the store at the time are close contacts who must get tested today, and casual plus contacts who went the drive-thru should also get tested today. Both groups should isolate until receiving a negative result.

On Friday, Prime Minister Jacinda Ardern said she was, "like everyone, frustrated" about the person who went to work at KFC.

"We want people to do the right thing because that's what keeps everyone safe."

Despite this, she is warning against a "mass pile [on]" of the person in question, as that might create an environment where people are too afraid to get tested.

She is asking for everyone who may have come into contact with the new case to "do the right thing" and isolate.

And if they don't, she is sounding a warning: "There is a section 70 order".

That order means a medical officer of health can oblige people to isolate.

"We have some legal footing for that ... and so there are repercussions," Ardern said.

Earlier on Saturday, prior to the latest community case being revealed, there was only one Covid-19 case in managed isolation.