A labour minister claimed today that a carcinogenic drug may have entered the food chain through horses slaughtered in Britain.
Shadow environment secretary Mary Creagh (pictured)told the Commons she had evidence that "several" horses slaughtered in Britain last year tested positive for phenylbutazone.
Ms Creagh said: "I am in receipt of evidence showing that several horses slaughtered in UK abattoirs last year tested positive for phenylbutazone, or bute, a drug which causes cancer in humans and is banned from the human food chain.
"It is possible that those animals entered the human food chain."
Unison meat hygiene official Ian Adderley highlighted that government cuts to the National Equine Database meant that the horse meat passport system wasn't working.
He said: "The only way to make sure that horse meat is safe to eat is to increase inspection and testing."
The Food Standards Agency said: "Horses which have been treated with phenylbutazone or 'bute' are not allowed to enter the food chain."