Tests carried out today on five birds found dead on the River Bann near Portglenone, Co Antrim, and another that was found near Moira, Co Down have returned negative for bird flu.
The bodies of the birds, understood to be swans, had been taken for an examination by scientists at the non-governmental Agriculture Biosciences Institute laboratory at Newforge in south Belfast.
The results returned this evening proved negative for bird flu.
Earlier today a Government-appointed expert group met following the confirmation that a swan found dead in Scotland was killed by avian flu.
A sample from the mute swan found dead on a harbour slipway in the village of Cellardyke on the east coast of Scotland tested positive yesterday for the H5N1 strain of avian flu, which can be fatal in humans.
Tests are being carried out today on 14 other birds in Scotland.
Although the H5N1 strain, which affects wild birds and poultry, does not easily pass from human to human, there are concerns it could mutate into a human illness. If this occurred, it would spread rapidly as humans have almost no resistance to it.
A dead swan found in Meath yesterday and a sick swan found at a Dublin location are being examined by veterinary experts in Dublin.
Minister for Agriculture and Food Mary Coughlan insisted yesterday that while the Scottish case had increased the risk of the virus arriving here, there was a "high level of preparedness". "We were on a low to medium risk," she said.
Fine Gael agriculture spokesman Dennis Naughton attacked the Government this morning, claiming there was a slow response to "a disease that could devastate our economy".
Mr Naughton said Fine Gael conducted a phone survey of Garda stations last night to see if they knew the Government's emergency bird flu helpline number.
Twelve out of 16 stations did not know the number, he said, adding that one garda told him to contact the ISPCA. "These instances highlight the fact that critical information on containing bird flu in suspected cases is not getting out into the public domain," he claimed.
In response, Ms Coughlan pointed out that the telephone number has been widely advertised in national newspapers on several occasions. It can be reached on 1890-252283.
The helpline received 98 calls yesterday.
Ms Coughlan said she was "disappointed that [Mr Naughton] seemed more intent on creating unnecessary anxiety among the public than constructively assisting ongoing efforts in preparing to deal with avian influenza should an outbreak occur here".
She said she had been fully engaged with senior officials since the Department first became aware of the case in Scotland on Wednesday. She said plans to deal with a possible outbreak in Ireland were "evolving" and all developments would be taken into account in any policy decisions.