Frenzi Group Ltd director Roy Thompson, a member of the Queenstown alcohol working party, said he was shocked to discover a bottle of beer can be bought from Fresh Choice supermarket for the equivalent of $1.22 - 18.6% cheaper than if his company bought almost 39,000 bottles of Speight's in bulk from Lion Breweries.
Mr Thompson said the liquor industry took the blame for patrons' drunken behaviour and ran the risk of heavy fines if it served people who were already intoxicated.
However, he believed young revellers were often getting "pre-loaded" on cut-price supermarket alcoholic drinks, despite assurances from supermarkets in May they would stop selling alcoholic drinks below cost.
Mr Thompson's comments follow a move by the Law Commission (which is considering ways to make cheap alcohol more expensive in an attempt to discourage young and problem drinkers), to ascertain through the New Zealand Retailers Association, from supermarkets, how much alcohol they are selling, broken down by price.
The association has declined the commission's requests.
Fresh Choice Queenstown is part of the Fresh Choice franchise group and is owned and operated locally.
Wholesale Distributors Ltd is the franchise owner.
Wholesale Distributors operations manager Robert Smith, of Christchurch, said in a statement the company was a responsible retailer and adhered to strict policies on alcohol sales.
"We believe the vast majority of our customers purchase alcohol as part of their basket of goods. A very small percentage buy alcohol on its own.
"At this time of year, suppliers commonly lower their prices to us, and we are able to pass the savings on to customers."
Lion Nathan communications manager Judy Walter, of Auckland, said liquor retailers set the price at which alcoholic beverages were sold.
"By law, we, as a producer, cannot stipulate a price - either maximum or minimum."
When asked at what prices Lion Nathan sold its products to supermarkets, corporate affairs director Liz Read, of Auckland, said Lion Nathan did not publicise its commercial arrangements.
"Prices are just one lever. There are lots of options to encourage people to regulate their drinking. For example, making it illegal to drink in a public place.
"At the moment, the law allows publicans not to permit entry to patrons who are already intoxicated."
Regulators needed to be "very cautious" when looking at ways to increase pricing to reduce excessive alcohol consumption, Ms Read said.
"Across-the-board, price increases will simply penalise the vast majority of responsible adult drinkers and do little to change the behaviour of those who drink excessively."
Foodstuffs South Island Ltd retail general manager Alan Malcolmson, of Christchurch, said: "The New World group do not sell beer under cost.
We have an industry agreement and adhere to that absolutely."
Mr Malcolmson said he did not have a comment on pre-loading as it was "subjective".
Mr Thompson bought two packs of 18 bottles of Speight's from Fresh Choice last week for $43.98, or $21.99 a pack.
He said he would pay $28.53 if he, as a publican, bought an 18-pack from Lion Breweries, based on the company's current wholesale price list.
"If I place the largest bulk order that they list, that's 24 pallets, each pallet contains 90 cases, Lion Breweries' biggest bulk discount cuts in when you buy 38,880 bottles of the product, at which point the price becomes $27.01, including GST.
"And that represents 18.6% above what Fresh Choice is currently selling."
Mr Thompson said even if Fresh Choice had obtained further price rebates from Lion Breweries, he did not believe rebates would lower the price to this extent.
"Fresh Choice is in the business of selling Speight's to 18-year-olds at $1.22 per bottle, which is cheaper than water and speaks for itself.
"We've been in the hospitality business for 11 years and every night of the week we have 300 staff serving customers all around the country.
"I'm not aware of us ever being fined for serving underage or intoxicated customers, yet night after night, we have to deal with the issue of pre-loading, whereby particularly younger people are getting often highly intoxicated at home on cheap alcohol they've particularly bought from supermarkets.
"Yet, we're the ones who have to employ security guards to keep them out and clean up after them and, at the same time, we get the bad press, because people assume wrongly businesses like ours are responsible for creating these levels of intoxication."
Mr Thompson said he wanted honesty and transparency in the way supermarkets price alcohol promotions, so the public can understand the root causes behind alcohol-related problems on the streets.
Price disincentives were the only meaningful way to limit excessive alcohol consumption among young drinkers, he said.
Sergeant Keith Newell, the alcohol harm reduction officer in Queenstown, said he acknowledged that people "pre-loaded" at home to save money before they paid bar prices.
"We notice that happens around midnight when people come into town.
"There's people still wandering around town at 3am or 4am and you can't tell me they're walking around for fun. They're going from bar to bar."