Further to the arrests made yesterday in Todmorden and Wales in relation to suspected fraud, there have been seizures of evidence in Hull and London.
The Food Standards Agency said officers entered three premises with local authorities and the police; one was in Hull and two in Tottenham.
Computers and documentary evidence has been removed as well as meat samples that have been taken for testing.
Yesterday, the FSA announced that three individuals - one in Todmorden and two in Wales - had been arrested by Dyfed-Powys Police on suspicion of fraud, as a result of the Agency’s investigation into the use of horse meat in the food chain.
The investigation is live and ongoing and the agency said it would not be making any further comments regarding those arrests.
The FSA has continued to provide information to Europol and this information has now been analysed by both Europol and law enforcement agencies in 35 countries – across Europe and elsewhere.