Tests carried out at the Institute for Animal Health in Pirbright, Surrey, on pig samples taken from a Co Antrim slaughterhouse have proved negative.
Restrictions on the abattoir at the centre of a foot-and-mouth alert were lifted yesterday evening.
The alarm was raised after lesions were found on the feet of a pig. Although the tests were preliminary, it was considered safe to remove restrictions.
The results were confirmed yesterday afternoon by the department of agriculture and rural development in Northern Ireland and by the Department of Agriculture and Food in Dublin.
Movement restrictions and other conditions were imposed by Northern Ireland's chief veterinary officer, Bert Houston, at the abattoir and the premises of origin after the lesions were detected.
Officials feared the symptoms could have been linked to swine vesicular disease, or foot-and-mouth, which paralysed food production and tourism across Britain and Ireland in 2001.