Experts told AAP FactCheck that New Zealand recorded negative excess deaths in 2021, when the vaccine rollout began.

The claim is made in a video shared on November 30, 2023, by prominent anti-vaccination activist Liz Gunn, but has since been taken down.

Ms Gunn is a former journalist and founder of NZLoyal, a populist party which received 1.2 per cent of the vote in New Zealand's general election in October.

The video is still being shared by members of the anti-vaccination movement in New Zealand and Australia.

It features Barry Young, a data administrator at Health New Zealand (Te Whatu Ora) who allegedly downloaded and shared vaccination data which is now subject to a non-publication order.

Mr Young has been charged with dishonestly accessing a computer. He has pleaded not guilty and elected a trial by jury. Health New Zealand is also conducting an investigation.

These events follow a previous video Ms Gunn published on October 21, when she claimed data from an unnamed whistleblower showed tens of thousands of deaths in New Zealand were linked to COVID-19 vaccines. AAP FactCheck debunked those claims.

The caption of the latest video reads: "The irrefutable data on New Zealand's excess deaths from the Covid jabs."

Ms Gunn interviews Mr Young, who shows her various data tables and graphs.

“What I did was run a query to see how many days where more than 120 people were dying … it was just a magic number, it was just a line in the sand that seemed appropriate for New Zealand, we’re a small country,” he explains.

Health New Zealand chief executive Margie Apa said in a statement that Mr Young had "no clinical background or expert vaccine knowledge". 

Experts also told AAP FactCheck the claims in the video were false.

Michael Baker, an epidemiologist at the University of Otago, said excess mortality rates were below zero during the vaccine rollout period.

Professor Baker pointed to a graph from Our World in Data which shows the cumulative number of deaths from all causes compared to a projection based on previous years.

"The interpretation is that COVID-19 elimination during 2020-21 was highly effective at preventing COVID-19 deaths, and provided the unplanned additional benefit of also reducing deaths from influenza and other respiratory infection," he said.

"Hence we saw large numbers of lives saved in 2020-21. 2021 was the year of highest vaccination, and a period when the excess mortality rate continued to fall."

University of Auckland vaccinologist Helen Petousis-Harris cited the same dataset.

"NZ has had one of the highest COVID-19 vaccine uptake rates in the world and one of the lowest mortality rates (negative excess)," Associate Professor Petousis-Harris said.

Janine Paynter, a vaccine safety expert also at the University of Auckland, agreed there were lower deaths than usual in 2020 and 2021.

A spokesperson for Stats NZ told AAP FactCheck there were several ways to measure excess deaths and other calculations could show a slight increase for 2021.

This includes the method of comparing deaths in 2021 to a historical three-year average. Total deaths in 2021 were 34,932, which was 1324 higher than the average across 2017-2019.

But this does not take into account population changes such as ageing, migration and fertility.

Prof Baker said there was a “big jump” in excess mortality in 2022 relative to previous years, with 38,574 deaths recorded.

“These high numbers were driven by both population growth and the COVID pandemic,” he said.

“There was no evidence of an association with (the) vaccine.”

Michael Plank, an expert in mathematical epidemiology at the University of Canterbury, agreed.

“The timing of the peaks in deaths (March-August 2022) coincides with large waves of COVID-19 in New Zealand, not with the vaccine rollout, the bulk of which was in July-December 2021,” Professor Plank told AAP FactCheck.

Stats NZ reported almost two in every three deaths in 2022 were people aged 75 years or older.

Dr Paynter said the age-standardised death rate, which can be used to compare different years because it accounts for population changes, was steady over the pandemic period.

Figures from Stats NZ show the mortality rate in 2022 was 3.55 people per 1000, compared to the 2015-2019 average of 3.54.

Dr Petousis-Harris said the lack of transparency was one of several reasons why Mr Young’s data was unreliable.

She noted the population demographics of the dataset were unknown, it was not clear what methodology had been used and the analysis did not follow the scientific method.

New Zealand's Ministry of Health has said four deaths are possibly linked to COVID-19 vaccination.