Consumer group Which? said it has found “concerning” loyalty scheme pricing practices at a number of high street chains and supermarkets.
This includes a number of products being listed at member-only promotional prices for more than half of the year, according to the group’s investigation.
It comes as the UK competition watchdog is currently analysing whether displayed savings are genuine.
Last month, the Competition and Markets Authority (CMA) was looking into whether non-member, or regular, prices may have been artificially inflated by supermarkets to make their loyalty prices appear more attractive, but its initial findings indicated retailers are unlikely to be misleading shoppers.
On Thursday, Which? said it had analysed the pricing history of almost 12,000 products at health and beauty retailers and supermarkets over the past year to uncover how genuine the loyalty savings were.
As part of this, it found that one in six (16%) Superdrug products on a loyalty offer had been at the non-member price for less than half the time.
At Boots it was one in 10, and for supermarkets, it was 10% at Tesco, 5% at Sainsbury’s and 3% at Co-op.
Which? said it also identified cases where prices were raised to a higher price for a relatively brief period before going on “offer”.
It said that at Boots an Oral-B iO7 electric toothbrush (blue) was at a non-member price of £400, while the members’ price was £150. This product had only been £400 for 13 days beforehand, prior to which it was £150 for everyone, according to Which?
A Superdrug spokeswoman said: “Our products are regularly on a mixture of members’-only prices, multibuy promos, and price promotions open to all, to ensure all our customers can make savings on their favourite products throughout the year.
“Every month we give our loyal Health & Beautycard members access to hundreds of health and beauty products at a lower price, and the investigation highlights the value this offers our members.”
A Boots spokesman said: “We have always been committed to offering customers great value, helping them save money across their health and beauty needs.
“All promotions, including Price Advantage, are assessed against all applicable laws and guidelines set out by the Chartered Trading Standards Institute.”
A Sainsbury’s spokesman said: “More people are choosing to shop at Sainsbury’s and we know our customers are savvy shoppers, who understand that factors like inflation, products falling out of season, or promotions can affect our prices.
“That doesn’t stop us following pricing guidance for the industry and offering great value on the products our customers buy most – whether that’s with our Low Everyday Prices, Aldi Price Match or Nectar Prices.”
A Co-op spokesman said: “We know our member prices provide true value for our members.
“No base prices have increased to accommodate Co-op member pricing and, in fact, many of the ‘all-customer’ prices were decreased to ensure Co-op was competitive on key lines for all shoppers, whether they are a member or not.”