(KCEN) -- Tuesday's raids were the first by British officials investigating a slaughterhouse suspected of passing horsemeat for beef.
The story has angered consumers and led retailers to pull products from store shelves.
Selling horsemeat is not illegal in Britain, but eating it is nearly taboo.
The British government said anyone found to have fraudulently sold horsemeat should be prosecuted.
Andrew Rhodes with the Food Standards Agency said, "Clearly that's unacceptable and we've seized all of the products in that location as well as all of the paperwork as well as any other evidence that we need as part of our investigation."
The agency that regulates food safety said it suspended operations at facilities in northern England and Wales while it investigates their possible involvement in the scandal.
