It spent three months collecting information from undercover gamblers at more than 100 venues across New Zealand, with only one stopping the operator acting as someone unable to control their betting.
Venues are supposed to be able to identify those with gambling problems, but the investigation showed this was not occurring.
“To be honest we were somewhat surprised at the extent of the issue that we have now uncovered,” Maarten Quivooy from Internal Affairs told ONE News.
“To then come back and find that actually all of those situations our mystery shoppers were not approached, were not offered assistance. I think is really concerning.
“We’ll now be working with them and watching really closely to make sure they step up to the plate.”