A number of vehicles, cash and electronic devices have been seized during searches in Co Monaghan as part of an investigation into international smuggling activities.
The Criminal Assets Bureau has been investigating a group suspected of being involved in international smuggling activities for over a year.
Gardaí have said the investigation - which is not connected to the Essex police investigation into 39 deaths - has intensified over the past two weeks.
A number of financial accounts have been restricted and last week a Northern Ireland-registered tractor and trailer was seized at Dublin Port. A Bulgarian registered tractor unit and a curtain sider trailer were also detained.
Warrants were issued for 10 separate sites in Co Monaghan on Thursday. Seven homes and three yards/industrial sheds were searched, where four vehicles, documents, electronic devices as well as sums of cash were seized.
No arrests were made and the investigation is ongoing.