This marks the first time British suppliers have been involved in the scandal since it broke in January. Previously, contaminated food had been traced to factories in Poland and Romania.

The Food Standards Agency raided the Peter Boddy Licensed slaughterhouse in West Yorkshire yesterday, as well as the West Wales processing company, Farmbox.

FSA officials believe that horses were slaughtered in the UK with the horsemeat being passed off as lamb for kebabs and beef for burgers, in the latest in a series of food standards revelations. 

The FSA said both companies was selling horse meat passed off as beef, though the agency didn’t know which retailers had stocked it. Both companies are licensed to kill horses, and both deny the charges that they’ve been misleading the public.

Boddy’s son told The Daily Telegraph that the charges were “a load of hype” and “crap”. Dafydd Raw-Rees, who owns Farmbox Meats, said that he was recently contracted to process horse meat sold in Belgium.