There has been a massive privacy breach, with the leak of personal details revealing the identity of New Zealand's 18 active Covid cases.

RNZ reports seeing a document that includes the full names, addresses, age and the names of the hotel and one hospital the 18 have been quarantining in.

The State Services Commission has been called in to make sure a "thorough investigation" is held.

State Services Minister Chris Hipkins says the fact this personal information had been given out was totally unacceptable, and he has ordered an investigation.

National Party leader Todd Muller also says the major leak of personal details revealing the identity of New Zealand's active cases is unacceptable, calling it 'shabby”.

"I have been advised by the Ministry of Health that at this stage it cannot be confirmed beyond doubt whether a deliberate leak was involved or if this was simply human error,” says Hipkins.

"If it was the former, it is unconscionable and absolutely beggars belief why anyone would feel it was an acceptable action to take, given the trauma it is likely to cause those whose information is involved. It would, quite frankly, be abhorrent, and potentially criminal.

"Either way", says Hipkins, "it cannot happen again.

"The public has every right to expect their private information to be held securely."

The personal information relates to 18 people who have tested positive for Covid-19 and who are quarantining in both the North and South Islands.

There are no new cases of Covid-19 in the country today, marking the fourth day of no new cases this week.

Todd Muller said the breach was "quite staggering, it talks to a government that's slipping off the side of a cliff, in terms of managing this issue, the border, the information pertaining to it".

"If they can't manage personal information, bluntly, they can't manage the border and they can't manage the country,” says Muller

From the National Party's perspective, Muller said it was "unacceptable" and they would see where it ended up.

"Is it a deliberate leak or is it accidental? It doesn't really matter at a level ... it's loose, it's shabby and it's a reminder these guys can't manage important things well," says Muller.

"These guys need to step aside and let a competent government take over."

He would wait to see "how it all unfolded", Muller says, but it talked to a culture within the government which was "pervasive".

"Sloppy, not disciplined, not focused on delivering,” says Muller.

The State Services Minister Chris Hipkins says the government will do everything it can to track down who is responsible for a massive privacy breach relating to New Zealand's active Covid cases, and is not ruling out pursuing criminal charges.

Ultimately, if there are avenues available to us to pursue somebody who's done this maliciously then we'll certainly be exploring those, this is not the sort of thing that I am willing to let go," says Hipkins.

"This is a major breach of trust and confidence and it should be rigorously pursued."

He was "very, very angry" such highly sensitive information was leaked, but said the source was still unknown.

It would be "abhorrent" if it was a deliberate act, Hipkins says.

The information is held by a number of agencies and by some involved in the management of managed isolation and quarantine facilities.

The National Party's spokesperson for health, Michael Woodhouse, said this was "yet another serious failing" that showed the government was not capable of managing Covid-19.

"This is unconscionable and unacceptable that those suffering from the incredibly dangerous virus now have to suffer further with their private details being leaked," says Woodhouse in a statement.

He says the government needed to get to the bottom of the source of the leak, and added that "keeping confidential information confidential should not be a difficult task".

"The Ministry of Health have been assuring people since the beginning of the epidemic in New Zealand that personal details would remain private, it's unfathomable that they couldn't handle a simple task like this,” says Woodhouse.

The State Services Commission has been asked to work with all of the relevant agencies, he said, as at the moment there were several government agencies involved. He said at this point "we don't have certainty about where in the process the information has ended up being released".

"To identify what the record keeping practices are, who has access to the information, how it came into the public domain, I want them to do that really thoroughly, I want them to leave no stone unturned."

Motive also had to be determined, Hipkins says, whether it was a mistake "and then someone took advantage of the mistake they made, or whether it was more malicious than that".

Someone "impartial" would be brought in to carry out the investigation, which may also involve forensic analysis of IT systems, the minister says.

"I think it's important that we bring someone in who's not directly involved ... which is what the State Services Commissioner will help to facilitate,” says Hipkins.

He has a message for the thousands of people coming through the border regime, who are obliged to hand over personal information.

"On behalf of the whole government, and I'm not sure where in the government the system has fallen down, I can apologise to those people, this is not acceptable, no government should tolerate this kind of behaviour and we won't.

"And I want to give an absolute assurance that we will get to the bottom of it, and that we will make sure it doesn't happen again and that anyone who has acted maliciously will be held accountable for that."

In a statement today the Ministry of Health says the total number of confirmed case was at 1180, with just 18 active cases.

One person remains in Auckland City Hospital in stable condition.

One significant cluster remains open and is due to close on July 6.

Yesterday, 2900 tests were completed, bringing the total number of tests to date to 411,932.

Yesterday was the third day in a week where there was zero new cases reported, although two new cases were reported in managed isolation on Monday and a further two on Thursday.

Meanwhile, cases of the novel coronavirus across the world have soared past 11 million, according to a Reuters tally.

Travellers coming from New Zealand will no longer need to isolate once they arrive in England from July 10, in an easing of restrictions announced today.

If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs) or call your GP - don't show up at a medical centre.

Jane Patterson/RNZ