It's now been a week since a tipster alerted police that two people broke Auckland's strict Covid-19 lockdown rules, travelling to their Wānaka bolthole, but police are yet to lay charges.

During that same time, other high-profile lockdown breach allegations have come and gone - including the arrests of three Aucklanders accused of having gone skiing at Mt Ruapehu and the arrest of a man who posted video of a cross-border Macca's run on social media.

So why haven't police yet filed charges against the Wānaka holidaymakers - the son of a district court judge and a lawyer - even though they've issued a public apology acknowledging their actions? The delay isn't particularly surprising, one legal expert says.

"When you arrest the child of a judge, you want to get the details right," said retired University of Auckland law professor Bill Hodge, pointing out that the couple have also hired a QC lawyer who is undoubtedly "looking over every step" of the investigation.

"They're taking great care, as we would hope they would. I think they're doing their best."

Replying to queries from the Herald on Friday, a police spokesperson said they appreciate the high amount of public interest in the case.

"We can assure our community that Police is carrying out a thorough investigation into this matter," the spokesperson said.

William Willis, 35, and Hannah Rawnsley, 26, were confronted by police in Wānaka on the afternoon of Saturday, September 11, after someone reported their trip a day earlier through the Covid-19 online compliance tool.

Police allege the couple used essential worker exemptions to leave Auckland but then went on to Hamilton Airport, catching a commercial flight to Queenstown and driving a rental car to the holiday home. In the week since police approached the couple, it has become the highest-profile Covid-19 lockdown breach allegation of Auckland's nearly month-long Delta outbreak.

The couple "will be prosecuted for breaching the current Health Order, by failing to return to their place of residence within the alert level 4 area after leaving for approved essential personal movement" and will be "issued with a summons to appear in court in the coming week", police said Sunday evening in a media statement expressing frustration at "a small number of disappointing incidents ... at Auckland's southern boundary in recent days".

"This calculated and deliberate flouting of the alert level 4 restrictions is completely unacceptable and will be extremely upsetting to all those who are working hard and making great sacrifices in order to stamp out Covid in our community," police said in the statement.

But in an unusual teleconference with a judge on Monday evening, in which lawyer Rachael Reed QC sought emergency name suppression for the couple even though they hadn't yet been charged, a police representative appeared to take on a more cautious tone.

"He responsibly noted that because of the alert level 4 court restrictions currently in place in Auckland, there might be some delay either in charge filing or first appearance," Wellington-based Judge Bruce Davidson, who was assigned the hearing to avoid a conflict of interest in the Auckland courts, noted in his ruling the next day.

On Monday, following intense media interest in the case, a police spokesperson told the Herald they are "considering our enforcement options available to us and a decision on any charges has not been made at this stage".

The couple gave up the fight for name suppression - and suppression of Willis' relation to a district court judge - on Tuesday night, admitting their decision to visit Wānaka last "was completely irresponsible and inexcusable".

"We are deeply sorry for our actions and would like to unreservedly apologise to the Wānaka community, and to all the people of Aotearoa New Zealand, for what we did," the couple said in a statement issued to the media. "We understand that strict compliance is required to stamp out Covid-19 from our country. We have let everyone down with our actions, and we wholeheartedly apologise."

While other lockdown breach allegations have made headlines in recent weeks, it's important to note that they're not all the same from the point of view of an investigator, Hodge said.

The three essential workers from Auckland allegedly caught at Mt Ruapehu's Turoa Ski Field on Wednesday were arrested a short time later in nearby Ōhakune on Covid-19 lockdown-related charges.

On Monday, a man with essential worker paperwork posted a video on TikTok boasting about crossing the border for a McDonald's run. When approached by police about the video, he said the post was made "just to get views" but he was actually travelling to Waikato for legitimate work. Police investigated, and he also was arrested this week.

But the Wānaka case, Hodge pointed out, would involve an investigator tracing a person's steps through multiple cities.

"It's potentially a lot more complicated - they want to make sure they can show the pre-meditation," Hodge said. "If there's tracking that you can follow from one airport to another to a rental car agency, I think that it would take a lot longer as opposed to an idiot who says, 'Let's drive over the hill and go to McDonald's.'

"It's a lot more travel, a lot more planning and a lot more stops to get where they're going."

Officials have pointed to swift police action in other cases, including the three skiers from Auckland.

In a press release issued today, Ruapehu Mayor Don Cameron thanked police for their quick action in charging the people, "which sends a clear message to any others thinking of doing anything similar".

It was a sentiment echoed by Inspector Nigel Allan, the police area commander for Whanganui Ruapehu.

"As shown by the actions taken today where people choose to deliberately breach the restriction in place, police will take enforcement action," he said.

Speaking to the Herald about the Wānaka case on Friday, a police spokesperson also emophasised that not all cases are the same.

"Every breach we come across is assessed individually to determine what inquiries need to be carried out," the spokesperson said. "Some breach reports require more inquiries to be made than others and these can take some time to be completed.

"At this stage, Police is still making inquiries and we are not able to comment further while it is under investigation."

Hodge said he has full confidence that police in New Zealand will treat those accused of recent lockdown breaches the same, even if it doesn't necessarily result in people getting arrested on the same timescale.

"If you're dealing with the son or daughter of a judge, you don't want to make any procedural mistakes - that's for sure," he said.