Labor backbencher Marisa Paterson said it was "completely unacceptable" an investigation by the ACT Gambling and Racing Commission around the death of Raimon "Ray" Kasurinen had taken four years.
She has called for urgent changes to the commission's investigative provisions and for the Hellenic Club to be tightly monitored.
Mr Kasurinen died by suicide in 2020 and his family have blamed the Hellenic Club for not doing more to stop him pouring his money into poker machines.
The ACT Gambling and Racing Commission is still investigating the matter four years on.
"I can barely speak to how angry this makes me feel, this family has been waiting four years to finalise its investigation and reach an outcome," Dr Paterson told the Assembly on Tuesday afternoon.
"I cannot possibly fathom what the commission has been doing for four years."
Dr Paterson pointed to other inquiries into other states which took far less time, including the NSW independent casino commission into Star Casino which took 10 months and the Royal Commission into Crown Melbourne which took nine months.
She said she doubted the ACT Gambling and Racing Commission was substantially resourced to conduct the investigation.
"I cannot see how the commissioner has performed its functions to the expectations of the Canberra community," she said.
Dr Paterson said it was also completely unacceptable Mr Kasurinen's family had not been provided any information on the investigation.
Prior to becoming an MLA, Dr Paterson was a gambling researcher at the Australian National University.
She is a member of the government but the Gaming Minister, Shane Rattenbury, is from the Greens. Dr Paterson is Labor's spokeswoman on gaming policy, a role she has taken up ahead of October's election.
She has called on the minister to change investigative provisions to prevent further harm to the family.
"I urgently call on Minister Rattenbury to urgently amend the investigative provisions to ensure that further trauma is not inflicted and the situation can never occur again," Dr Paterson said.
Dr Paterson also took aim at the Hellenic Club and called for the club to face tighter oversight while the investigation was ongoing.
The family of the deeply indebted gambler said the club plied him with free food and drink even as he poured money into the machines until just before dawn.
"The other issue I have is the complaints raised by the family, reported in The Canberra Times, are the worst of the worst. They alleged predatory, manipulative behaviour to encourage attendance at a venue and to play poker machines despite the alleged known harm that was occurring," Dr Paterson said.
"The fact that this investigation has been going on for four years without any extra scrutiny, sanctions, eyes on the venue, that it was allowed to operate business-as-usual for four years ongoing is absolutely not acceptable.
"If such serious harm has been alleged, and an investigation is four years ongoing, then there needs to be measures in place to monitor a venue's activities, until such time that an outcome of an investigation has been finalised."
The chief executive of the Hellenic Club, Ian Cameron, has told The Canberra Times: "Any claim that the Hellenic Club failed Mr Ray Kasurinen or his family or that there was any indication of potential gaming harm to him or them are unfounded and are denied by the club."
- The Gambling Helpline is on 1800 858 858.
- Support is available for those who may be distressed. Phone Lifeline 13 11 14; Men's Referral Service 1300 776 491; Kids Helpline 1800 551 800; beyondblue 1300 224 636; 1800-RESPECT 1800 737 732.
