A food scientist has suggested lamb products may also contain horse meat.
Dr. Mark Woolfe is a former head of authenticity at the Food Standards Agency (FSA) in Britain.
He says the products need to be tested.
It comes ahead of a meeting of Agriculture Ministers from across the European Union tomorrow to discuss the crisis of the discovery of equine DNA in beef products.
Minister: I can't be 100% sure
In the Dáil this afternoon Minister Simon Coveney has been quizzed about the traceability of horsemeat.
He admits there is not a 100% guarantee with the system of passports and microchips.
"Can I be 100% sure that no horse has got - essentially - a false passport? I can't be 100% sure of that" he said.
"All I can say is that we are putting as many checks in place as we can; and if anybody has any evidence to the contrary, we will follow up on that immediately" he added.
Meanwhile Fianna Fáil Senator Thomas Byrne says more EU leadership is needed on the crisis ahead the meeting tomorrow.