Eight million illicit cigarettes, worth an estimated £3m in lost duty and taxes, have been seized during a raid by police and HMRC officers in Newry.
The Joint Agency Task Force operation on Saturday morning also saw a heavy goods vehicle and its refrigerated unit seized, along with a van and a forklift truck.
A significant amount of cash - £12,000 and €2,000 – was also confiscated.
Three men, aged 34, 37 and 55, were arrested and remain in custody.
A number of further searches have since been carried in the Carlingford area of Co Louth by Revenue Commissioners and An Garda Síochána.
Almost €100,000 was seized, along with items including thousands of duty stamps, and approximately 2.5 tonnes of rolling tobacco worth over €1m.
Those trading in illicit cigarettes may be funding terrorism and criminality which brings misery and harm to local communities and today’s action sends a powerful message to those engaged in this type of criminality.
Steve Tracey, Assistant Director of HMRC’s Fraud Investigation Service, said: “Multi-agency investigations mounted by the Joint Agency Task Force show what can be achieved by our ongoing cross-jurisdictional cooperation to tackle criminality.
“Our collaboration, even during a global pandemic, demonstrates that we are committed to working with each other, at every level and in every location, to tackle organised crime on a cross-border basis.
“As we did today, we will take all measures necessary to ensure we can continue to carry out this important work successfully.”
An Garda Síochána’s Detective Superintendent Alan Cunningham added: “Through the Joint Agency Task Force, gardaí - along with other agencies -will continue to focus on organised crime groups involved in the illegal manufacture and distribution of tobacco, as it is used as a source of funding to support dissident republican activities.”
Investigations are said to be continuing.