Lidl customers have been warned some biscuits on sale at the supermarket could contain pieces of metal.

The supermarket has extended its recall of cookies to three new products following an initial warning earlier this week.

The Food Standards Agency (FSA) has also issued a “do not eat” warning.

The affected products in the original recall include the Tower Gate triple chocolate and lemon flavoured soft baked cookies, with best before dates of December 12 and December 13, and the Tower Gate chocolate chip cookies, with a best before date of December 14.

Lidl has now added the Tower Gate half coated chocolate chunk and fruit & nut cookies, with best before dates of December 6, to the recall, as well as the McEnnedy American Way Nougatelli, with a best before date of December 10.

Anyone who has purchased the recalled cookies should return them to Lidl for a full refund.

An FSA spokesman said: “Lidl is recalling the above products. Point of sale notices will be displayed in all retail stores that are selling these products.

“These notices explain to customers why the products are being recalled and tell them what to do if they have bought the products.

“If you have bought the above products do not eat them. Instead, return them to the store from where it was bought for a full refund.

“Any customers with queries or concerns can contact Lidl Customer Services on 0203 966 5566 or customer.care@lidl.co.uk for GB or 0289 568 4888 for NI.”

What is a product recall?

If there is a problem with a food product that means it should not be sold, then it might be 'withdrawn' (taken off the shelves) or 'recalled' (when customers are asked to return the product).

The FSA issues Product Withdrawal Information Notices and Product Recall Information Notices to let consumers and local authorities know about problems associated with food.

In some cases, a 'Food Alert for Action' is issued.

This provides local authorities with details of specific actions to be taken on behalf of consumers.