Detector dog Bill uncovered the money during searches yesterday
More than €24,500 in cash has been seized in Dundalk.
Two houses were searched in the area yesterday as part of an operation targeting the illegal sale, supply and importation of tobacco.
Detector dog Bill uncovered the money, with Revenue saying the cash is suspected to be either the proceeds of crime or intended for use in criminal activity.
Drogheda District Court today granted officers a three-month detention order to allow them carry out further investigations.
Revenue is calling on anyone who knows someone evading tax or involved in smuggling to contact their Confidential Freephone number at 1800-295-295.