A DRUG with the potential to cause cancer in humans might have entered the food chain through horse meat slaughtered in UK abattoirs, Labour has claimed.

Shadow environment secretary Mary Creagh told the Commons she had evidence that "several" horses slaughtered in the UK last year tested positive for the carcinogen phenylbutazone.

Agriculture minister David Heath told the Commons the Food Standards Agency checks all meat to ensure it is fit for human consumption. "Where positive results of phenylbutazone are found the FSA investigates and takes follow-up action to trace the meat," he told MPs.

Ms Creagh told the minister: "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."

She asked if Mr Heath was aware of the cases and the minister told her: "The Food Standards Agency carry out checks in slaughterhouses to ensure that equine animals presented for slaughter are fit for human consumption in the same way as they do for cattle, sheep and other animals.

"In addition, the FSA carry out subsequent testing for phenylbutazone and other veterinary medicines in meat from horses slaughtered in this country."

The claim that bute could have entered the food chain follows the separate revelation that burgers sold by Tesco and other supermarkets contained traces of horse meat.

Ms Creagh called on the Government to reverse a "reckless" decision to scrap the National Equine Database (NED).

Mr Heath said: "There is no difficulty in tracing the use of a horse passport. To suggest the National Equine Database was required to do that is simply erroneous."

© Press Association 2013