Labour’s claim that 70,000 horses had disappeared from Northern Ireland in recent times and possibly ended up in food were not recognised by a senior government vet during a committee meeting at Stormont.
Robert Huey, deputy chief veterinary officer in Northern Ireland, said: “I do not know what the basis of it is.”
Gerry McCurdy, director of the Food Standards Agency (FSA) in Northern Ireland, said the investigation into the source of the fraud had still some way to go, but added that differences in the cost of beef and horse offered an incentive for wrongdoing.
“If you are selling horsemeat, someone said for £700 a tonne versus £3,000 a tonne, for anyone who is in the game of being fraudulent there is an extremely helpful financial incentive there for them,” he said.
Two Stormont committees held a special meeting to debate the issue of contaminated meat.
Assembly members also questioned agriculture and environmental health officials.
Elements of a consignment of meat at Newry firm Freeza Meats was found to contain about 80 per cent horsemeat.
Assembly member Sue Ramsey said: “Public confidence has been shattered.”
Mr McCurdy said there was more demand for cheaper processed meat.
“The local beef is probably too expensive for those burgers. That still does not excuse supermarkets,” he added.
He said the information officials possessed would direct them towards some form of fraudulent activity, but it was unclear where that had taken place.
“The information available to us does point in the direction of Europe but we cannot be definitive about that at this point in time until those investigations are complete,” he said.
Mr McCurdy said 18 countries were now involved, and negotiations were going on with individual member states of the EU and the European Commission.
He said the “issue of horsemeat was not on our radar” until Irish authorities embarked on tests late last year.
Horse DNA was discovered at plants in Monaghan and Cavan in the Irish Republic, and in Yorkshire in January.
Mr McCurdy said regulators would have had to have been specifically searching for the presence of horsemeat to have detected it.