Police said they would be seeking a “waiver of diplomatic immunity in order to lay charges”. A waiver could be granted by a diplomat’s home country.

Electoral law expert Graeme Edgeler told Newstalk ZB’s Jake Tame he thought there would be a “reasonable chance” police would get the diplomatic immunity waived in this instance, because Australia was the country involved.

“I’m not aware of the last time this sort of thing happened with that country, but [with] these sort of relatively minor things, [it’s] quite common for something like this for the other country to say, ‘Okay, we’re going to waive it’,” he said.

Edgeler said diplomatic immunity was “basically a protection” from legal process. He said the law still applied to the person who had diplomatic immunity, but it couldn’t be enforced.

“Often it would be you shouldn’t even be arrested,” he said.

He added you couldn’t be prosecuted, sued or summonsed as a witness.

Asked if theoretically you could commit any crime, such as murder, Edgeler said yes.

“One of the things that can happen then is, if you have diplomatic immunity, New Zealand can say, ‘No we’re cancelling it and you’ve got a week to get out of the country’.

“[It’s] quite common in New Zealand, for New Zealand to seek permission from other countries that diplomatic immunity be waived.”

Edgeler said waiving of diplomatic immunity tended to be done on a “step-by-step basis”.

“Immunity” can be granted to diplomats and their families under international law – the Vienna Convention on Diplomatic Relations 1961.

It’s a long-standing principle designed to ensure diplomats and foreign representatives can perform their duties with freedom, independence and security, as the Ministry of Foreign Affairs and Trade (Mfat) explains.

Former British High Commissioner Vicki Treadell told the Herald previously this was particularly useful in countries with poor human rights.

Diplomatic immunity means a person cannot be arrested or detained, prosecuted or subpoenaed as a witness. They can, however, be issued a traffic infringement notice.

Mfat documents set out how the New Zealand Government expects the sending state – the country the diplomat is representing – to waive immunity of a foreign representative or accredited family member where a serious crime is alleged to allow for legal proceedings against the individual.

The definition of a “serious crime” here is one with a penalty of imprisonment of 12 months or more.

“Serious crimes therefore include offences against persons such as murder, manslaughter, sexual offences, and common assault; certain driving offences such as dangerous driving causing injury; and certain property offences including theft of more than $500,” Mfat documentation says.

An individual who is immune from local jurisdiction cannot waive their own immunity.

Immunity belongs to the sending state, not to the individual, and must be waived by the sending state, Mfat says.

In 2020, then Prime Minister Jacinda Ardern said she had spoken with South Korea’s President over disappointment that diplomatic immunity was not waived during the police investigations facing a South Korean diplomat.

In late August, the South Korean diplomat was given a suspended jail sentence after he was convicted of sexually assaulting a New Zealand staffer at a Wellington embassy.

In 2018, a landlord was left fuming at Mfat after it protected a foreign diplomat who owed $20,000 in rent and damage to the property.

The Tenancy Tribunal had ruled in favour of the Wellington landlords – but Mfat intervened, saying the proceeding should never have taken place because EU deputy head of mission Eva Tvarozkova had diplomatic immunity.

Benjamin Plummer is an Auckland-based reporter who covers breaking news. He has worked for the Herald since 2022.