Newshub can reveal that customers of Kiwibank are spending around $30 million every month playing on online gambling sites.
And that's just one bank's data.
It comes as Internal Affairs says a review to regulate online gambling is "ongoing", despite it being three years since the review was first announced.
Online gambling, whether it be pokies or playing live blackjack, is booming.
"When we look at our own customers, what we see is there is about $30 million a month that's being spent on online gambling and 80 percent of that is offshore," said Julia Jackson, Kiwibank's head of purpose and sustainability.
"It really is [an incredible amount] and what's a really interesting trend that we've seen is from the first COVID lockdown in 2020, that number has massively increased and it hasn't gone down."
The offshore sites raking in millions are based in places including Malta, Cyprus, Gibraltar, Estonia, and Lithuania, where registered companies benefit from low taxes and can offer internet gambling to anyone in the world.
SkyCity's Maltese-based online gambling business made $13.1 million last financial year. Although the company said it's a "relatively small player" when it comes to New Zealanders using its service.
Kiwibank uses a voluntary system, where customers can elect to have themselves blocked from spending cash on offshore sites.
"It essentially stops all online gambling transactions on their visa, debit, or credit cards," Jackson said.
More than $7.1 million has been saved by people using the block, but this is a Kiwibank initiative. The Government is yet to introduce any form of regulation for online gambling.
A review into online gambling was announced in July 2019. By mid-2020, public submissions were complete.
But even now, nothing's eventuated, with Internal Affairs saying the review is "ongoing and we are expecting Cabinet to consider options later this year".
Gambling addiction researcher at Auckland University of Technology Maria Bellringer said other countries only allow access to reputable sites.
"I'm well aware of the consultation that went on in 2019 and I was very surprised that nothing came of it to date and disappointed," she said.
- If you know more, email Michael Morrah in confidence at firstname.lastname@example.org
A Cabinet paper was written, but its author said it was a contentious issue and former Racing Minister Winston Peters stopped it ahead of the 2020 election.
"It was a meeting in his office, with his staff, where he explained that the timing was probably not the best," said former Internal Affairs Minister Tracey Martin.
"That paper never found its way to Cabinet."
But Peters told Newshub it had nothing to do with the election, and was more about the need to further improve the legislation.
"Not at all. It's nothing to do with timing," he said.
"When we looked at it, there were too many loose ends.
"The record will show that a whole lot more work needed to be done on this."
Bellringer said that "something needs to be done" about online gambling.
"I think a lot of people don't realise what they're getting into with online gambling," she said.
"Online gambling is a high-risk factor for developing problem gambling."
No one knows exactly how much in total New Zealanders spend, but Internal Affairs estimates it was at least $351 million on offshore gambling sites in the last financial year, not including money spent with Lotto NZ and the TAB, the only local online providers authorised to operate in New Zealand.
The other major banks were unable to say how much their customers spent on offshore gambling.
ASB Bank said it was considering introducing a voluntary option for customers who want to stop themselves spending money with online gambling businesses.
Westpac told Newshub it doesn't provide an option for customers to block their own spending.
"We regularly review our policies and controls around online gambling, and in February 2020 removed the ability for customers to earn loyalty points on gambling transactions," it said.
ANZ was approached for comment but is yet to respond.