The head of one of the UK's biggest supermarkets has urged shoppers not to panic about the food they buy. Iceland's chief executive Malcolm Walker used strong language to say it was impractical for all foods to be tested.

Mr Walker was interviewed by Panorama as part of an investigation into the horse meat scandal which revealed mounting public concerns about what is really in our food.

With industry insiders saying shoppers should prepare themselves for more uncomfortable truths, Richard Bilton asks whether 'light touch' regulation of the food industry has left the stable door open to cowboys.

Iceland was one of the supermarket chains caught up in the crisis when the Irish Food Standards Agency said some Iceland burgers contained horse DNA. Their products subsequently passed the British tests - which only show positive at more than 1 percent horse DNA trace.

Panorama: What's really in our food? BBC One, Monday, 18 February at 20:30 GMT and then available in the UK on the BBC iPlayer.