The government's claims that horse meat may have reached British consumers via practises in Europe were looking increasingly flimsy today, after two raids took place against British meat processing firms.
West Yorkshire company Peter Boddy Licensed Slaughterhouse and Welsh firm Farmbox Meats were suspended from supplying food by the FSA last night.
"We've been very relentless in this. We'll continue following it through until there is nothing left to find," FSA director of operations Andrew Rhodes said.
"There is a completely legitimate trade in horsemeat, and nobody wants to frustrate that, but there isn't a legitimate trade in substituting one meat for another."
Environment secretary Owen Paterson travels to Brussels today to hold discussions with European ministers.
Meanwhile, supermarket chiefs have been accused of quashing a food safety group which gathered information on rogue suppliers which may have blocked the horse meat entering the market as beef.