It follows allegations reported by trade publication Farmer’s Weekly that pork products from the company ended up in items such as ready meals, quiches and sandwiches sold by UK supermarkets.

The publication claimed that the meat supplier, which has not been named for legal reasons, sold mislabelled and sometimes rotten pork until at least 2020.

The FSA warned that food supply chain fraud could be “increasing” as a result of rampant cost inflation in the industry.

Andrew Quinn, deputy head of the FSA’s National Food Crime Unit, said: “The FSA’s National Food Crime Unit is carrying out a criminal investigation into how one supplier allegedly provided products labelled as British when they were in fact sourced from South America and Europe.

“The initial retailer was notified at the same time the NFCU acted against the food business suspected of the fraud.

“We are looking into all new lines of inquiry with our partner organisations, including any potential food hygiene breaches, and acting where necessary to protect public health.

“At a time when cost pressures and other challenges mean the risks of food fraud might be increasing, it is vital that everyone involved in the food chain works to ensure that food is safe and what it says it is.”

On behalf of supermarkets affected, the British Retail Consortium said: “The role of the Food Standards Agency is to work with retailers to prevent fraud.

“Whilst we cannot comment on an ongoing investigation, retailers will support the FSA with its investigation into the individual supplier in question.”

It comes after the NFCU earlier this month said pre-packed meat and deli products from South America and Europe had been supplied to an unnamed supermarket and labelled as British.

The NFCU said the retailer in question has now removed all affected products from its shelves.