Polish authorities say they have found no traces of horse DNA at five meat plants which supply Irish companies. 

Results from a sixth plant are due to be released on Monday. 

It comes after the Minister for Agriculture Simon Coveney said the source of the contamination at the SilverCrest plant in Co Monaghan was a Polish ingredient. 

Gabriel Gilmartin of the Irish Sheep and Cattle Farmers Association says the plant's owners need to clarify the sourcing of their ingredients.