Prime Minister Jacinda Ardern referred questions on the Government blunder that sent Northland into an 11-day lockdown to former Covid Minister Chris Hipkins.

New documents released under the Official Information Act have revealed the truth about the highly publicised case of three women who travelled from Auckland to Northland in October 2021 in the midst of a Delta outbreak, putting Northland into an alert level 3 lockdown.

The OIA papers show the women - who had earlier been blamed for using "false information" to get travel permits - had no links to gangs and weren't sex workers, as had been suggested, and their permit had been approved in error.

Hipkins claimed there was nothing new in today's reporting as the error that led to the Northland lockdown in October last year was made public.

"It's a matter of record at the time that a clerical error was admitted at the time," Hipkins said.

"Our first and foremost priority at that time was to protect the people of Northland as much as we could."

Northland was sent into an 11-day lockdown after Covid-19 was discovered in the region. Photo / Dean Purcell

Hipkins said the whole context needed to be considered - and he referenced the low vaccination rates, new cases of Covid being in Northland and the limited spread of Delta outside Auckland.

Asked whether he would apologise to the women who travelled into Northland and faced public backlash, Hipkins said he didn't want to get into "all the ins and outs" of the situation, saying decisions were made on the information available and acknowledged much of that information was not completely confirmed.

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However, he said the decision to send Northland into lockdown was the right one.

Hipkins said he was made aware of the error at some point during the investigation, but reiterated it had been made public at the time.

He accepted allegations relating to the women were made at the time, but said he was "pushing back" on them and noted the allegations - some made by former Deputy Prime Minister Winston Peters - were "not particularly helpful".

Minister of Social Development Carmel Sepuloni, who was briefed on the error made by MSD staff, said it was a "human error". She said "there was a lot going on in terms of the context of Covid" that led to the decision-making there.

Among the documents released was a summary of a police investigation into the women which found "no offence" and no "deception" in obtaining the travel documents.

Detective Inspector Aaron Proctor's summary of "Operation Hiking" quoted an email from the Ministry of Business, Innovation and Employment which said the travel documents were "issued in error by the Ministry of Social Development, (the error not being the fault of the applicant)".

Another document showed it was known three days before the 11-day lockdown was announced on October 8 that human error was behind the travel documents being granted to the women.

Speaking to Newstalk ZB's Mike Hosking this morning, outgoing Far North Mayor John Carter was outraged by the revelations.

"It just pisses you off, it makes you angry. This is just typical of the invisible, arrogant Wellington bureaucracy."

Outgoing Far North Mayor John Carter was frustrated by the revelations. Photo / Michael Cunningham

Housing Minister Dr Megan Woods, also speaking to Hosking this morning, said she did not know anything about the incident, other than what has been reported in the Herald today.

"I think one of the things that I do know is that if you cast your mind back there to that time - huge concern in Northland around Delta getting in and the transmission of Covid.

"It was a low vaccination population and from my understanding, it wasn't a clerical error that shut the border, it was the presence of Covid."

Put to her that the two women involved in the incident would not have been in Northland had it not been for a clerical error, Woods said a lockdown was used so there was no transmission of Covid-19 in the community.

Asked if the Government owed anyone an apology, she said: "It's too early for me to say."

Housing minister Dr Megan Woods. Photo / Mark Mitchell

Ardern, who is in Auckland celebrating a milestone for the Government's Apprenticeship Boost programme, will speak with media about 10am.

In a statement this morning, Act Party leader David Seymour called on Ardern to detail when her ministers knew of the mistake.

"It was a disgraceful period where the Government was light on information, and rumour and innuendo filled the void. Two travelling women were accused of being prostitutes.

"ACT called for the Government to front up and give the facts, but it took an OIA request a year later to uncover the truth.

"Each Minister, [Chris] Hipkins, [Stuart] Nash, and [Carmel] Sepuloni should state what they knew and when."

The women were publicly vilified for crossing the border with then Covid-19 Response Minister Chris Hipkins accusing them of using "false information to travel across the border".

The case also saw reporters quizzing Ardern over whether the women were prostitutes and former Deputy Prime Minister Winston Peters was forced to apologise for falsely claiming the pair were helped by Hawke's Bay-based Mongrel Mob leader Harry Tam.

The police inquiry summary said: "The police investigation found no evidence to suggest that (the women) had any connection to Harry Tam, the Mongrel Mob or were involved in prostitution."

On October 13, a briefing took place from MBIE to Hipkins, Finance Minister Grant Robertson and Regional Development Minister Stuart Nash.

The briefing said: "It is our understanding that the intention was to decline the application but it was approved in error."