The supermarket is recalling four products as they are "unsafe to eat".

The items affected are:

• Six-pack cheese and onion rolls (best before date: 31 August)

• Tesco Finest steak and ale pies (best before date: 1 September)

• Nine-pack mini pork sausage rolls (best before date: 30 August)

• 20 pack of mini pork sausage rolls (best before date: 29 August)

Anyone who has bought these items can return them in stores for a full refund. No receipt is required, according to the alert by the Food Standards Agency.

"We have been made aware that specific batches of various Tesco chilled products may have been contaminated with small pieces of blue plastic and metal," Tesco said.

"This could potentially pose a risk if consumed.

"Tesco apologises to our customers for any inconvenience caused," it said in a statement.

If there is a problem with a food product, the Food Standards Agency can either withdraw the product from supermarket shelves or recall it - asking customers to return the food.