Department of Agriculture officials are waiting to interview a man who delivered sheep now at the centre of a Foot and Mouth disease scare in Armagh to a processing plant in Roscommon.
The 248 lambs are believed to have been part of a load which passed through a farm, in Meigh in Co. Armagh.
They were supposed to be immediately slaughtered.
The northern authorities believe the farm which is just one mile from the border, will test positive for the disease.
The sheep were finally delivered to the Kepak processing plant in Athleague in Co. Roscommon, but the company say the animals were not the property of the farmer, in whose name they were supplied.
As a result 12 farms have been placed under surveillance.