The meat was supplied by an unnamed company in Europe and a spokesperson for Taco Bell said immediate action was taken: “We immediately withdrew it from sale, and discontinued purchase of that meat and contacted the Food Standards Agency with this information. We apologise to our customers and take this matter very seriously as food quality is our highest priority.”

The news comes as fast-food giant McDonald’s confirmed its products were clear of any horse meat contamination.

Jill McDonald, chief executive officer for McDonald’s UK said: “The reports of horse meat in some food products over the last few weeks has understandably raised questions about the provenance and integrity of meat products sold in the UK.

“I’m pleased to say that McDonald’s has not been affected. All tests, including our own have now been completed and we can confirm that no horse meat has been found in any of McDonald’s products.

“We only use whole cuts of British and Irish beef, sourced from traceable, quality-assured farms. Our burgers are made from 100% beef with nothing added except a pinch of salt and pepper after cooking.

"We don't use any binders, fillers or trimmings in our burgers. Our beef supply chain is short and transparent and has just five simple steps from the farms through to the food we serve in our restaurants.”