"I think it's particularly tragic when all of the oxygen that could be used for alcohol reform is being used up in cannabis reform. Alcohol causes a lot more harm to the community than cannabis does."
But Sellman said behind-the-scenes lobbying by the alcohol industry has stymied attempts at tougher regulation.
He said governments know what they have to do to improve the situation in relation to alcohol, but have repeatedly failed to do it.
"What we need to do is what has been talked about now for two decades: we have to dismantle the marketing of alcohol; increase the price; decrease the accessibility; raise the purchase age and further strengthen drink-driving counter measures."
He blames the political inaction on lobbying by the alcohol industry.
"There is an enormous amount that goes on behind the scenes that prevents governments, good governments, from acting and I think that there is unfortunately an influence on government through big money that corrupts the progression of good public health initiatives."
He said governments have been ignoring calls to regulate alcohol sales and marketing for two decades, and allowing big business the same free hand in the cannabis market would be disastrous.
"If the model that the government brings up looks anything like big business involvement in cannabis then I think as a country we should be really worried about that because we can see what big business does in terms of alcohol."
New Zealanders will vote whether to legalise recreational cannabis at the 2020 election.
80 percent NZers drinking responsibly - NZ Alcohol Beverages Council
The New Zealand Alcohol Beverages Council says that 80 per cent of New Zealanders are drinking responsibly, and overall consumption has dropped 25 per cent since the 1970s and 80s.
But its executive director Bridget MacDonald admits more work is needed to reduce harmful drinking.
She said it was going to take time and an all-of-society approach to change New Zealand's drinking culture, and points to the industry's targeted education and support programmes.
However, Dr Nicky Jackson from Alcohol Healthwatch is sceptical that self-regulation by the industry can work.
She said the market is dominated by huge multinational companies, which take 80 per cent of the profits offshore.
"New Zealanders in no way benefits from our heavy drinking culture, 46 per cent of all alcohol consumed in this country is consumed in heavy drinking occasions - this is our dominant drinking pattern, it's the same pattern that the industry needs to maintain to maintain profits."
Meanwhile, researchers estimate the cost of alcohol-related harm to New Zealanders at $8b a year.
Jackson said cheap and plentiful alcohol is costing us dearly.
"The deaths are only the tip of the iceberg. Alcohol impacts individuals, families, communities and there are huge inequities in the harm in this country.
Health Minister David Clark said addressing New Zealand's long standing challenges with alcohol would take a significant change in attitude across all communities.
The Health Ministry is working through recommendations from the Mental Health Inquiry, including those on alcohol sale and supply, he said.
These were informed in part by the 2010 Law Commission Review and the 2014 Ministerial Forum on Alcohol Advertising and Sponsorship.
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call 111.
If you need to talk to someone, the following free helplines operate 24/7:
DEPRESSION HELPLINE: 0800 111 757
LIFELINE: 0800 543 354
NEED TO TALK? Call or text 1737
SAMARITANS: 0800 726 666
YOUTHLINE: 0800 376 633 or text 234
ALCOHOLDRUGHELP: Call 0800 787 797 or text 8681
There are lots of places to get support. For others, click here.
- RNZ