A slaughterhouse is under investigation after undercover footage allegedly showed "sheep having their throats repeatedly cut".
Malik Food Group's (MFG) in Burnley, Lancashire, has had Welfare Enforcement Notices issued by the government after a film taken over two days emerged.
The Food Standards Agency (FSA) reviewed 70 hours of footage taken between 2-21 March by Animal Aid.
The FSA said animal welfare was a "high priority". MFG is yet to comment.
Animal Aid said it had "uncovered barbaric and deliberate cruelty being inflicted on animals".
It claimed that sheep were filmed at Dunnockshaw farm "having their throats repeatedly cut, as many as seven times in one case, in contravention of the law".
The charity alleges it was because the slaughterman failed to maintain a surgically sharp knife.
Luke Steele from the charity said the footage showed "horrific scenes... unlike any we have ever seen before".
The FSA said it takes all alleged breaches "extremely seriously".
It said it has taken immediate enforcement action against both the business operator and individual staff and revoked slaughterman certificates of competence.
"Our investigations into this establishment continue but to say more at this stage could be prejudicial to any future potential criminal proceedings."
Malik Food Group said on its website it is the UK's leading processor of halal mutton, lamb and beef.
It said it ensures sheep and lambs are slaughtered by Muslim slaughtermen "adhering to the highest principles of halal animal welfare".