Agriculture Minister Simon Coveney has told the Dáil his department is investigating a number of complaints about forged documents in the Irish horse-slaughtering industry.
However, the Minister refused to say exactly how many complaints were being examined, and what action was being taken.
It is feared that horse passports, which certify that an animal is safe to enter the food chain, are being forged and linked with animals which are banned from being part of the chain.
The news comes after new fears that lamb products may also contain horsemeat, after a British food scientist suggested the products should be tested.
In the Dáil Minister Simon Coveney said: "Where forged or tampered passports accompanying horses to slaughter are detected, it is policy that such animals are destroyed and removed from the food chain.
"I can confirm that my department has received a small number of complaints (of passport manipulation)."