The admissions by Walker and veteran spin doctor Michelle Boag follow the government’s announcement yesterday of a sweeping inquiry to find the source of the leak.

National MP Hamish Walker has disclosed that he engineered a privacy breach over the weekend when he purposefully released the personal details of Covid-19 patients at the country’s border facilities to the media.

Walker said in a statement that the release of information was meant “to expose the government’s shortcomings so they would be rectified”. The government said before Walker’s confession that the privacy breach was serious and may have been a criminal act. A full inquiry was launched yesterday.

Moments after Walker’s disclosure, National Party insider Michelle Boag said in a separate statement that she had given the information to Walker. Boag, who was the National Party’s president in 2002, was the acting chief executive of Auckland Rescue Helicopter Trust but has now resigned from the trust. She said she didn’t expect Walker to release the information to the media.

National leader Todd Muller has stripped Walker, the Clutha-Southland MP, of his shadow portfolios due to his “error of judgement” and said he is awaiting the results of the inquiry into the leak before commenting further.

Walker said that he released the data to highlight the lack of security on the health information held by the government. In what he called an apology, he said he now hopes the government improves its protocols.

“It was never intended that the personal details would be made public, and they have not been, either by me or the persons I forwarded them to,” said Walker. The data was released to a number of media organisations over the weekend, which all declined to publicise the personal information of all 18 active Covid-19 cases last Friday.

Walker said he has received legal advice that he has not committed any criminal offence.

“I made serious allegations against the government’s Covid-19 response and passed on this information to prove those allegations,” said Walker.

Boag said she had access to the information only in her role as acting CEO of the helicopter trust. “This was a massive error of judgement on my part,” she said in a statement. “I very much regret my actions and did not anticipate that Hamish would choose to send it on to some media outlets but I am grateful that the media involved have chosen not to publish the 18 names that were contained within it.”

Speaking this evening, state services minister Chris Hipkins said that a sweeping inquiry under Michael Heron QC announced the previous day would continue. The inquiry is expected to conclude before the end of the month. Heron has the ability to summon witnesses, compel documents and question parties under oath.

“This is a very disappointing situation,” said Hipkins. “It does have a ring of dirty politics to it, and that would be very sad for the forthcoming election.”

The minister has asked agencies to look for ways they can improve their data-handling procedures.

After the personal information was leaked to the media, the opposition called it another sign of the government’s incompetence. Muller called the privacy breach, “loose, shabby and a reminder these guys can’t manage important things well”. He did not retract that criticism today.

According to Hipkins, the opposition leader should consider his critique. “Perhaps he might want to reflect on the comments that he made and consider whether or not he applies those to his members of parliament as well,” said the minister.

In a tweet, Ayesha Verrall, the infectious disease expert running for Labour who is widely believed to be a leading candidate for health minister should the party return to power, said that the opposition MP’s decision was “totally unethical”.

“This is patient information. Idea that it needed to be sent to media to make a point about privacy beggars belief,” she wrote.

Privacy commissioner John Edwards added this in a tweet: “Outrageous, unbelievable, indefensible.”

Asked at her post-cabinet press conference yesterday whether the leak might be “political”, Jacinda Ardern said: “When we have leaks of a political nature, we don’t take those kinds of steps but when this is someone’s personal health information, we do need to take that seriously. I don’t think there’s any politics in that.”

Today’s admission by Walker comes just days after he was accused of stirring up racist sentiment over the pandemic. On Thursday, in response to news the government is looking at setting up managed isolation and quarantine facilities in his region, Walker issued a press release saying it was “absolutely disgraceful” communities hadn’t been consulted.

“These people are possibly heading for Dunedin, Invercargill and Queenstown from India, Pakistan and Korea. I’ve already had many calls, texts and emails from residents who do not want people in quarantine in Queenstown.”