Police Minister Stuart Nash believes an investigation will show other National Party MPs or members were also involved in a Covid patient data leak.
Last night, MP Hamish Walker and former National Party president Michelle Boag confessed to being behind the massive privacy breach of Covid-19 patient information.
"I simply can't believe that this is just Michelle Boag and Hamish Walker. There'll be others' fingerprints all over this," Nash told Newstalk ZB this morning.
"Bill English and John Key would have handled this completely differently. This is a National Party problem at this point."
The National Party board is meeting today to decide the fate of the MP who leaked Covid-19 patient details and leader Todd Muller wants Walker out.
Muller has written to the party's board asking it to remove Walker from the party, RNZ reports.
Muller says there needs to be consequences for the leak and his advice to Walker was to "think deeply about what the honourable next step is".
Muller told Newstalk ZB's Mike Yardley that he was informed Monday lunchtime that Walker was the leaker and after the inquiry was announced, made it clear Walker had to co-operate.
He then sought legal advice and once receiving that, made it public.
Last night, Walker and former National Party president Michelle Boag confessed to being behind the massive privacy breach of Covid-19 patient information.
Police say they are waiting for a complaint to be laid before looking into the situation.
"If a complaint is received it will be assessed to determine the necessary action, if any, police will take," said a spokesman.
"We will not be making any further comment at this stage."
Muller wrote to the National Party board last night outlining concerns about Walker's judgment and it was meeting today.
"He's displayed some serious lack of judgment," he said.
"I've made it very, very clear how unacceptable his behaviour was and there was an expectation that this information was to be made public and that he co-operates with the inquiry."
Walker hasn't given Muller any indication yet whether he will step aside as National's Clutha-Southland candidate, he told Newstalk ZB.
Muller said he couldn't be precise around when the board would release its decision as it was its process.
National MP Mark Mitchell told Newstalk ZB's Mike Hosking Breakfast his party should deselect Walker as the candidate for Clutha Southland.
"Ultimately it's a decision for our board and the leader, but I think that it's a massive departure from our own set of values and what we stand for in the National Party.
"My own personal expectations would be that Hamish wouldn't be standing. It's sad, because he's done an outstanding job of advancing issues for his electorate, but he's shown a terrible lack of judgment on this one."
Mitchell said should be reflecting on whether he should voluntarily stand down as an electorate candidate.
"It's terrible, difficult situation. He's got a young wife, he's got a new young daughter, but there's no excuse for leaking personal information, so I hope he is reflecting on that today."
Mitchell said it is up to the board to discuss Michelle Boag's future in the party.
Muller said he's lost confidence in Walker.
"I wrote to the board last night setting out concerns I had with respect to his judgement. They're going to meet today and reflect on that."
When asked whether he'd discussed with Walker that he stand down, Muller said: "I certainly requested that he reflect deeply on what sits inside of him and I was very, very clear around my disappointment and very clear around the consequences that happened immediately in terms of the demotion and the loss of the portfolios."
Muller told MediaWorks that Boag's actions "were appalling" and believed the board should also consider her actions. Muller said he wasn't able to strip her of her National Party membership - that was a decision for the board.
Muller said he didn't have "a huge amount" of connection with her, besides the occasional party function.
"She has lost a lot of trust in my mind."
The Labour Party could call it "dirty politics" if they wished, said Muller, and he wouldn't buy into that conversation.
Muller said after he was told Walker was the leaker on Monday, he then connected Walker with his chief press secretary. He then got legal letters and sought legal counsel himself as it had become "very clear" the inquiry needed to be informed.
"I received a notification lunchtime Monday then asked Hamish to connect with my chief press secretary and chief of staff. And then, of course, we found out the inquiry was happening and it became very clear to me, very clear, that we needed to inform that inquiry of what we knew," he told MediaWorks.
"I then shared that expectation with Hamish and then I received legal representation, which of course put me in a position of needing to check my own legal position before I made it very clear that that information needed to become public. That roughly took 24 hours - it is what it is, that's how it happened. It was never going to be moved from the course that this information needed to be made public and it was."
Muller told TVNZ's Breakfast that Boag didn't tell anyone in the National Party she'd sent Walker the information.
Muller said he was "hugely disappointed, angry actually" about Walker.
They would both need to face the consequences of their actions, he said.
He was asked whether he would prefer if Walker wasn't the Clutha-Southland candidate and replied: "Yes."
He said he, the National Party and their supporters didn't stand for that behaviour.
Boag is involved in deputy leader Nikki Kaye's electoral campaign and Muller said his "personal view" was Boag should step aside from having any involvement with the party.
Muller said he had "no idea" what the motive was behind the pair's actions.
Jacinda Ardern told The Country that Walker's political future is a decision for his leader Todd Muller and the National Party.
But she says the Government will continue the investigation into what happened with people's health information.
"We still need to give ourselves assurances that we've done what we should have done with our health information correctly in our systems, even though that information has been used for political purposes, which is obviously completely inappropriate."
Walker admits the leak
Walker admitted sending the details of 18 active cases to the Herald and two other media outlets last week while Boag revealed she'd sent the information to him.
• Covid-19 coronavirus: National MP Hamish Walker, Michelle Boag admit leaking patient details
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• Covid 19 coronavirus patients' details leaked: Investigation launched as agencies scramble
• Covid 19 privacy breach: Criminal charges 'on the table' if malicious motive behind leak of personal details
Boag said she was sent the information through her role as acting chief executive of the Auckland Rescue Helicopter Trust. She has resigned from that role.
Walker sent the spreadsheet containing the patient's private information - including their names, dates of birth and where they tested positive - in response to being called racist.
He believed by naming the patients it would prove he was right the active cases were from "India, Pakistan and Korea", as he'd claimed in a press release.
The spreadsheet did not prove that.
Walker last night claimed he'd sent the document to prove the "serious allegations" he'd made against the Government.
"I did this to expose the Government's shortcomings so they would be rectified. 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."
Walker said he had received legal advice that he had not committed any criminal offence.
"The information that I received was not password-protected by the Government. It was not stored on a secure system where authorised people needed to log on. There was no redaction to protect patient details, and no confidentiality statement on the document.
"By exposing a significant privacy issue I hope the Government will improve its protocols and get its safeguards right."
Privacy Commissioner John Edwards said he believed the deliberate leak of the information was illegal and in breach of the Privacy Act.
Muller said in a statement last night he had asked Walker to co-operate fully with the Government's inquiry, headed by Michael Heron, QC.
"I have expressed to Hamish my view that forwarding on this information was an error of judgment.
"While I wait for the result of the inquiry I have transferred his forestry, land information and associate tourism portfolio responsibilities to Ian McKelvie."
Boag said she'd made a "massive error of judgment on my part" and apologised for doing so.
"The information was made available to me in my position as then acting CEO of the Auckland Rescue Helicopter Trust (ARHT), although it was sent to my private email address.
"This was a massive error of judgment on my part and I apologise to my colleagues at ARHT whom I have let down badly.
"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."
Boag said she has resigned her position as acting chief executive of ARHT because of her conduct.
"My actions were mine alone and should not reflect at all on the professionalism, integrity and outstanding reputation of the Rescue Helicopter staff.
"They are an amazing bunch of dedicated community servants and I know they will be very disappointed in me."
State Services Minister Chris Hipkins says investigations will continue, despite the pair's admissions.
It was "disappointing" that there were politicians involved in the leak, he said, and it had a "ring of dirty politics to it".
The Heron investigation will be looking into why Boag had the information.