A business is under investigation by trading standards officers after a woman was hospitalised when the firm used a chocolate hazelnut dessert topping instead of chocolate.
West Yorkshire Trading Standards said the business in Bradford had served the topping on a dessert despite the customer informing staff they had a nut allergy.
Another investigation by the organisation looked into a separate firm in the city which had served an undercover officer gluten-free food that was later found to contain high levels of gluten.
Councillors will discuss the findings as part of an annual update on the work of West Yorkshire Joint Services, which runs trading standards.
