Three men have been arrested at meat plants inspected by the Food Standards Agency, Dyfed-Powys Police said.
Two men have been arrested at Farmhouse Meats near Aberystywth, west Wales and another man has been arrested at the Peter Boddy Slaughterhouse in Todmorden, West Yorkshire.
All three have been arrested on suspicion of fraud, and are being interviewed by police and FSA staff.
More top news
The BBC, The Daily Mail, The Guardian, and Buzzfeed were among organisations not allowed access to a government meeting.
Mexico's Foreign Minister has warned Donald Trump against imposing a tax to pay for a border wall between the two nations.
Rain will affect many northern areas at first, pushing further south through the day.