The Centre for Food Safety today advised people not to eat certain batches of crisps from Walkers Snack Foods Ltd as they might contain yellow rubber pieces.

The centre has also asked the trade to stop selling the products concerned.

The affected products are Walkers Crisps with a best before date of January 17, 2009 and code of "GBL ***306" - the asterisks can be any numbers.

Pack formats potentially affected are: Walkers Crisps Standard 34.5g Cheese and Onion, Ready Salted, Salt and Vinegar flavours; Walkers Crisps Big Eat 50g Cheese and Onion flavours; Walkers Crisps 150g Ready Salted, and Salt & Vinegar flavours; Walkers Crisps 14-pack Cheese & Onion, Variety flavours; Walkers Crisps 28-pack Cheese & Onion, Variety flavours; Walkers Crisps 24-pack Variety flavour.