Consumer body Which? has accused retailers including Tesco, Waitrose and Sainsbury’s of flouting rules governing special offers on wine and other products.

A Which? investigation found that some of the UK’s leading supermarkets had misled consumers by touting items as being on sale for ‘half-price’ – having sold the products at full-price for only a week beforehand.

Sainsbury’s was found to have sold wine as ‘£1 off’ for a five-week period, restoring the full price for just one week before putting the items back to the lower rate.

Marks & Spencer was found to be selling ‘half-price’ cherries for £2.49, when their full price was only £2.99, while Waitrose blueberries selling at £1.99 had only ever been sold at their higher price for two weeks.

Tesco, meanwhile, was found to have similarly misled shoppers over strawberries.

The investigation follows the introduction earlier this year of the Consumer Protection from Unfair Trading Regulations Act, which aims to prevent consumers being duped by bogus offers.

All the retailers involved in the report said they had not intended to mislead shoppers.

“[The] report has highlighted a few incidents where signage had not been updated and training will be repeated to avoid this happening in future,” a Sainsbury’s spokesperson told Which?.