The French government has banned the import of live cattle from Ireland despite assurances from the Minister for Agriculture, Mr Walsh, that there was "no indication whatever of foot-and-mouth disease in the Republic of Ireland".
As the Minister for the Environment, Mr Demspey, said the State was now "almost on a war footing" against the disease, it was announced that the Dublin and Cork St Patrick's Day parades have been cancelled.
The Northern authorities confirmed yesterday that all 21 sheep in Meigh, Co Armagh, had been infected by the disease and it is examining yet another suspected case in Cookstown, Co Tyrone. Confirmed cases in Britain rose to 31 yesterday.
Mr Walsh announced a criminal investigation into the illegal importation of 248 lambs into the Republic last week which has already seen a livestock dealer taken into RUC custody and a police search in Wales for an Irish farmer based in the midlands.
The Irishman is understood to be pivotal in unravelling the mystery arrival of sheep from the North at Athleague Kepak factory, Co Roscommon, but the man is no longer at his home in Co Offaly.
The Northern Ireland dealer's family said the man had gone to Banbridge RUC station voluntarily and claimed he had done nothing wrong. He was released late last night.
The owner of the farm where the North's first case of foot and mouth was identified, Mr Maurice Collins, said through his solicitor last night that he neither "owned, hauled, bought nor sold the sheep".
He said he had given full details of the identities of the people involved with the sheep to Northern department officials.
Mr Walsh said yesterday he had "no evidence that the sheep had moved through Meigh but suspected they had".
He said he was satisfied that the 248 lambs slaughtered in Athleague were now accounted for and had come through the North, probably from Meigh.
He said sheep tested in Co Wexford were negative and so were tests on farms connected to the Athleague plant.
The Department of Agriculture announced last night the reopening of the AIBP plant in Nenagh, Co Tipperary, which had been temporarily closed while an animal was being tested for the disease. The tests proved negative.
Meanwhile, the French authorities yesterday complained that Ireland's safeguards were not strong enough to keep the disease out of their country. They considered a ban on meat products but settled for a temporary ban on live cattle.
However, Department of Agriculture sources indicated that they were concerned that other countries may follow and that they were working with French veterinary officials to reassure them of the safety controls in place here.
State forests, national parks and public monuments are all closed. Mr Walsh has asked the main churches to consider not holding services, especially in the exclusion zone in Co Louth.
He said that if there was public co-operation he was certain the disease could be kept at bay.
Meanwhile, there was further bad news for racing fans with the news that the Cheltenham race track falls within the exclusion zone of a suspected outbreak in Britain.
Cheltenham officials face a 48-hour wait before test results are likely to emerge from the suspected outbreak on a farm less than five miles from the race track.