22 separate business premises were targeted with unannounced inspections in the Tullamore area as part of the search operation on Thursday.
The searches were carried out as part of an investigation into suspected abuses of the Department of Social Welfare and social welfare fraud, identified following cooperation between officers from the GNIB, the Workplace Relations Commission (WRC) and the Department of Social Protection.
Amid the operation on Thursday, five men aged from 38 to 47 years were arrested.
The five arrests relate to offences contrary to Section 12 of the Immigration Act, 2004 and Section 2(1) of The Employment Permits Act 2003.
All five men were charged with these offences and bailed to appear before Tullamore District Court on October 13th.