Police prosecutors say that dozens of supermarket operators in the South Island are "courting danger" with their promotional practices, as they face the prospect of a week-long liquor licence suspension.
Inspector Ian Paulin has sought the suspension of liquor licences for 35 New World stores throughout the South Island for an alleged violation of The Sale and Supply of Alcohol Act.
The breaches relate to the online promotion of DB Export Gold and Ultra Low Carb products on 9 January, that was advertised at a 26.1 percent mark down for club card owners.
Under Section 237 1B of the Act, the promotion of discounts of alcohol products of more than 25 percent is prohibited, unless on licenced premises.
A two day hearing in front of the Alcohol Regulatory and Licensing Authority in the Christchurch District Court ended on Tuesday, with prosecutors seeking a five day suspension for all 35 licensees in their closing statements.
The police prosecutor also asked the authority to consider a "negative holding" under the Act.
Both the prosecution and the defence delivered their closing arguments during the final day, with judge Simon Menzies reserving his decision to a later date.
The prosecution said the facts in the case were "inarguable" and that the licence-holders were trying to "shield themselves away from liability by hiding behind a complex corporate structure".
Centralised online promotions for the supermarket stores is handled by its co-operative Foodstuffs South Island (FSSI).
"Liability should not shift from the licensees, they are responsible for the liability," the prosecutor said.
"They must bear the burden."
On Monday, the authority heard evidence of prior breaches during December.
The prosecution submitted a total of 44 infringements were made on the New World website on 6 December, with discounts mostly ranging between the 30-40 percent mark.
Although one instance included the promotion of a Waiata Sauvignon Blanc advertised at a 53 percent discount.
Defence lawyer Iain Thain argued the breach was at the "lower end of the scale" and the result of "an honest mistake" because a final pricing check was not carried out at FSSI's end, who were acting as agents for the stores.
"I can't submit that this system is perfect and foolproof.
"The applications are against the individual stores, the licensees.
"They knew these were centralised promotions that they can't control."
Both Judge Menzies and member Judith Moorhead countered this, asking the defence whether the onus should be on the supermarkets to set up systems that ensured they complied with the law.
"How can a whole system fall down by one person going on holiday," Moorhead said.
Thain proposed the punishment be "reasonable and proportionate".
"They (the stores) haven't done anything ... what have they done?"
In his evidence on Monday, Foodstuffs' head of category and promotions Justin Waddell said they had implemented a software upgrade that automatically blocks promotions of more than 24.99 percent.
In response to the defence's closing submissions, prosecutors said having the threshold set at this mark was "courting danger" given how often shelf prices could fluctuate per day.
"Imagine any other retailer that wasn't a supermarket, coming before the authority saying 'I got someone else to do my advertising, I never check it, I relied on them 100 percent, we've got some vague guidelines'.
"Never in a million years would you accept that these were reasonable steps."
There is a total of 40 New World stores throughout the South Island.