The Commerce Commission is warning it isn't afraid to prosecute supermarkets after Consumer New Zealand received 80 complaints of dodgy price specials.
It comes after Consumer NZ lodged a complaint with the Commerce Commission, asking it to investigate Woolworths and Foodstuffs stores for potential breaches of the Fair Trading Act.
In June alone, supermarkets were seen to have 18 instances of people being charged more than the advertised price, 11 misleading multi-buys and 21 specials that were not special.
It's also been revealed supermarkets are the most complained about sector regarding possible Fair Trading Act breaches.
Commerce Commission chair John Small told AM on Thursday they've prosecuted supermarkets before and will do it again if necessary.
Small told AM co-host Laura Tupou they previously prosecuted the Mangere Pak'nSave and fined them $78,000 for price discrepancies in 2020
"We're very conscious of how we spend the public money obviously, so we can only take cases that we're confident are going to stack up and we try and triage the large number of inquiries and complaints we get so that we can get the best results overall," she said.
The key for the Commerce Commission to launch an investigation is to get good-quality evidence.
"The quality of evidence depends on what the complainant provides. For example, if you just call up and say, 'I bought a bottle of shampoo and they charge me a different price', that's not really sufficient evidence," Small explained.
"If you have a photo of the shelf ticket and a receipt and you can tell us who you are, where you bought it, when you bought it, that's good quality evidence. In order to make these things stand up in court, you need good quality evidence."
Small told AM even if the check-out operator fixes the price when it's brought to their attention, people can still lodge a complaint about price discrepancies.
"There are probably quite a few other people in that situation who have also been overcharged but haven't noticed, so we take it very seriously when we get good quality evidence of a mismatch between pricing on the ticket and at the till," he said.
The Commerce Commission is hoping supermarkets can get their "act together" because Small believes it's disappointing to see examples of dodgy supermarket specials still occurring.
"The broader picture here is we really want the supermarkets to get their act together and comply with the law," he said.
"They've got a complex business model, but it is their business model and they do have to have to get it right. I wrote to them myself in May and said this is a serious issue you need to get your act together. So it is disappointing to see it still coming up."
Foodstuffs spokesperson Emma Wooster said the accusations of misleading pricing behaviour are concerning for their grocers.
"We're happy to respond to any customer issues at any time, although this does require some basic information for us to look into properly and we have continually asked Consumer NZ to provide this information," Wooster told Newshub in a statement.
"Consumer NZ's continued use of the slogan "dodgy supermarket specials" and repeated accusations of 'widespread', 'systemic' and 'misleading pricing' behaviour is concerning for our grocers, putting stress, pressure and wellbeing impact on their front-line teams in-store over the nine months Consumer NZ have been running their campaign."
But the company also said Consumer NZ's claims around their customer's trust don't stack up with findings from past independent surveys.
Watch the full interview with John Small in the video above.