Revealed: The truth about supermarket 'bargains'
5 December 2011 Last updated at 07:12 GMT
The UK's 'big four' supermarkets stand accused of misleading shoppers with confusing and untrue claims about their special offers which could potentially leave them open to prosecution.
The BBC's Panorama programme has uncovered a series of pricing flaws at Asda, Morrisons, Tesco and Sainsbury's. Experts say some are in breach of consumer protection regulations.
Sophie Raworth reports.
Panorama: The Truth About Supermarket Price Wars, BBC One, Monday, 5 December at 20:30 GMT and then available in the UK on the BBC iPlayer.