SkyCity is accused of failing to uphold its host responsibilities due to the amount of time one customer was able to spend gambling between August 2017 and February 2021.
The news has prompted organisations like the Problem Gambling Foundation and Asian Family Services to call for more robust gambling harm reduction measures.
It was now up to the Gambling Commission to decide whether or not to suspend the casino giant's licence after a customer complained about how long they were able to spend gambling over the three-and-a-half year period.
The Department of Internal Affairs said this was in breach of SkyCity's harm-minimisation obligations, and recommended cancelling its licence for 10 days or so.
Problem Gambling Foundation spokesperson Andree Froude said the department was to be applauded for taking such quick action.
''It sends a clear signal to other gambling providers that they are required by law to provide effective host responsibility and that breaches have consequences," Froude said.
"So it is good to see, without having all the details, that some action is being taken."
Froude was also calling for a review of current harm reduction measures.
''New Zealand evidence suggests that people who gamble for three or more hours on casino pokies, have almost four times the risk of being a moderate or problem gambler, than someone who doesn't gamble on casino pokies.
"So we've actually strongly recommended that the timeframe of 5 hours of continuous play be reviewed."
Asian Family Services agreed.
National director Kelly Feng said more needed to be done to ensure services were accessible to non-English speakers.
''We know many Asians have little or lack of awareness of gambling harm and also the gambling addiction sites... there is very little information they have regarding help seeking behaviour," Feng said
Gambling rates in the community were high, she said.
''The Asian community experiences 10 times the harm of gambling harm in particular... it is much higher than the general population, like Māori and Pacifica as well, particular for casino type gambling."
Salvation Army's director of social services Lynette Hutson believed current measures and processes were fit for purpose.
But she said providers need to ensure staff were trained to identify problem gamblers.
''I think that the training that is available is fairly robust, I mean we have been doing this work for a long time, so we know the kind of triggers and symptoms. It's actually just a matter of the venues actually enforcing their training," she said.
Meanwhile, Forsyth Barr head of research Andy Bowley believed the financial impact if the licence was suspended, would be minimal.
''In isolation, the potential financial impact of a suspended licence for ten days is relatively material... so it could be a few percent of their profits in any one year, which isn't overly big," he said.
''The bigger question is what else is out there, that the DIA [Department of Internal Affairs] could be investigating."
But as of shortly after 3pm on Monday, around about $260 million was wiped off SkyCity's market value.
In a statement, SkyCity said it was committed to maintaining the highest standards of host responsibility best practice, with priority given to minimising the impacts associated with problem gambling.
SkyCity's Adelaide casino was also under scrutiny by Australian federal and state authorities for alleged breaches of anti-money laundering rules.