The Competition and Markets Authority (CMA) has been examining 10 product categories in a bid to see if shoppers, already struggling amid the continuing cost of living crisis, are being ripped off.

It said that while some increases were justified, to cover rising costs from elements such as energy and ingredients, there was clearly some profiteering.

"The evidence collected by the CMA indicates that, over the last two years, around three-quarters of branded suppliers in products such as infant formula, baked beans, mayonnaise, and pet food - have increased their unit profitability and, in doing so, have contributed to higher food price inflation", the statement said.

It added: "However, own-label products often provide cheaper alternatives with suppliers of these products earning lower profit margins and competing to win and retain contracts from retailers."

The CMA said that this competition meant that profit margins at branded suppliers had fallen due to weaker sales volumes as shoppers switched to cheaper, own label, alternatives.

The regulator said that more work was needed, including in the baby formula sphere that has been the subject of work by Sky News and seen the World Health Organisation declare that families were being "exploited".

The CMA issued its update after previously finding that higher prices in stores were not the result of weak competition between supermarket chains.

The watchdog did, however, demand tighter rules over so-called unit pricing - costs per item covering versions of the same product - to bolster price transparency.

It also previously found that supermarket fuel operators had charged motorists an extra £900m in 2022 by raising their margins on both petrol and diesel sales.