The Food Standards Agency (FSA) has begun an investigation after claims that traces of meat were found in food classified as vegan or vegetarian at two major supermarkets.

The information comes after The Daily Telegraph claimed to have tested ten vegan and vegetarian products at Tesco and Sainsbury’s and found meat in two of them.

The newspaper has said that laboratory tests found traces of pork in Sainsbury’s own brand “meat free” meatballs, and traces of turkey in Tesco’s Wicked Kitchen BBQ Butternut Mac 385g ready meal, which is labelled as a vegan product.

A Tesco spokesperson has said: “We take the quality and integrity of our products extremely seriously and understand that our vegan and vegetarian products should be exactly that.

“Our initial DNA tests have found no traces of animal DNA in the BBQ Butternut Mac product available in stores today. We would urge the Telegraph to share full details of their testing, including the lab used as we continue to investigate.”

A Sainsbury’s spokesperson has commented: “These products are produced at a meat-free factory. Sainsbury’s and the Vegetarian Society also carry out regular checks and no issues have been found.

“We have urgently investigated these findings, including extensive DNA analysis, and can find no evidence. Our investigation is ongoing.”

An FSA spokesperson said: “The Daily Telegraph has today shared information with us regarding the products they have tested. We are examining this information in relation to the allegations made over the weekend and will take appropriate action as necessary.”