The Minister for Agriculture, Mr Walsh, said last night he was "very reassured" by the response of the Northern authorities to concerns expressed about policing illegal sales of controlled animal drugs.
The concerns, arising from Irish Times revelations on Monday, were yesterday raised by officials from the Department of Agriculture with their Northern counterparts at the margins of the EU Farm Council here.
The Irish Times Agriculture Correspondent, Sean MacConnell, had reported that he bought prescription-only controlled drugs - ranging from clenbuterol ("Angel Dust") to steroids and strong antibiotics - with ease from vets in the North.
Their use in beef could cause serious problems to humans if not administered properly.
Officials in Dublin were in touch with Belfast on Monday about the issue. When it was raised again here yesterday, they were told the authorities took the question very seriously and would be carrying out an immediate investigation.
A spokesman for Mr Walsh said they had emphasised the need for the issue to be dealt with quickly. The Department shared the concerns expressed and its testing programme involved 100,000 animals last year. One per cent of those tested showed illegal levels of antibiotics or drugs, down from 4 per cent in 1993.
Unusually, yesterday's meeting was attended by a Northern Ireland Agriculture Minister, Sir Alf Dubs, who was in Brussels to take informal soundings from fellow ministers about their attitudes to lifting the ban on Northern beef.
The issue comes up today at the EU's Standing Veterinary Committee for a preliminary discussion on the proposed certified herd scheme but a decision is not expected until next Wednesday. It may then go to next month's Farm Council.
British sources said Sir Alf had received a good response. His main concern had been to emphasise the need to take the decision based on scientific advice rather than political considerations.
