Senior Muslim figures have said that they are shocked that a number of Walkers snacks contain traces of alcohol and eating them is therefore against their religion.
A tiny amount of alcohol is used in some products as a chemical agent to extract flavour.
The use of alcohol was discovered by Besharat Rehman, who owns a halal supermarket in Bradford, and reported in the Eastern Eye. Mr Rehman said: "Our suppliers were unaware of the alcohol. Walkers must make it clear on the packaging so customers can make an informed choice."
Shuja Shafi, who chairs the food standards committee of the Muslim Council of Britain, said that he intended to investigate. "Certainly we would find it very offensive to have eaten food with alcohol."