Sainsbury's said: "We have identified the possible presence of small pieces of metal in a number of batches of the below products. "As a precautionary measure, we are asking all customers who have bought any of the below products to check the following table and if they have an affected batch code, not to consume it, and to return it to their nearest Sainsbury's store where they will receive a full refund. "No other products or batch codes are affected by this issue, and we apologise for the inconvenience this has caused."