The Italian sauce company Saclà is recalling dozens of pesto products, including those sold as own brand by Waitrose and Aldi, over fears they may contain peanuts without declaring their presence.

The Food Standards Agency issued an allergy alert, warning that 25 products may be contaminated and pose a health risk to consumers with peanut allergies.

Aldi and Waitrose have both recalled the affected products and apologised for the inconvenience. They advised people with allergies against eating the products and encouraged customers to return them for a full refund.

Peanut allergy affects one in 50 children in the UK, according to Allergy UK, and can in severe cases and without an injection of epinephrine lead to a fatal anaphylactic shock.

Saclà said in a statement: “The health, safety and welfare of our customers is our number one priority. We took immediate action to recall every batch of every Saclà pesto recipe when we were made aware that some cashew nuts, which had been delivered by an external supplier, might contain traces of peanuts.

“Cashew nuts are an integral part of our pesto recipe, and so we therefore contacted all retailers, to ask them to immediately withdraw our pesto products from the shelves.

“Anyone who suffers from a peanut allergy should not consume any of these products, and should instead return them to the store where they made the purchase, or contact Saclà directly.

“We have launched an in-depth investigation into this incident and we are working very closely with the Food Standards Agency. We are extremely sorry that this has happened and we are doing everything we can to resolve the situation as quickly as possible.”

The FSA’s list of affected products includes: