Over 70 untagged cattle have been found by the Department of Agriculture's Special Investigation Unit (SIU) in raids on farms in west Cork.
The owners of the lands on which the animals were found have been given until tomorrow to provide proof of identity of the cattle or they will be seized and destroyed.
The first of the untagged animals were uncovered in raids on two farms in the Macroom and Dunmanway areas in January.
During the investigation, tags, farm registers and other equipment was removed from the farms, and unidentified cattle were tagged by the SIU team.
Early last month the farms were revisited with search warrants, and during the investigation DNA samples were taken from the animals involved.
During this part of the investigation, one of the SIU alleged he was assaulted, and his complaint is being investigated by gardaí.
Last week, the farmers who were under investigation were served with notices to provide proof of identity of the animals by tomorrow or the animals will be destroyed.
A total of 60 unidentified animals were found on one farm near Dunmanway, nine were found on a second farm and eight on another farm near Macroom. The team has been investigating the possibility that the animals may have been smuggled from the North.
The investigation is also focusing on whether the animals have been tested for bovine TB and brucellosis, and the team has been unable to uncover documentation to show that tests have taken place.
The SIU has been coming under increasing criticism from the Irish Farmers Association, which has accused it of using "heavy-handed tactics".
The Department of Agriculture and Food has denied the team has been exceeding its legal brief, and the Minister for Agriculture and Food has promised an SIU code of conduct.
