Undercover BBC reporters working for the Whistleblower documentary program said food at Tesco was re-packaged and re-labeled with a new date and reduced in price, sometimes days after it should have been sold or removed from the shelves.

In addition to falsifying food records, the retailers are accused of failing to ensure different knives for fish, raw and cooked meat are used to prevent cross-contamination of bacteria.

While the documentary said rules governing the amount of time fresh or frozen food is left outside of the fridge or freezer, it also highlighted the pressures faced by section managers not to waste money by throwing away food.