Four men have been arrested after the seizure of more than 11 million cigarettes in South Armagh, HMRC said.
HM Revenue and Customs (HMRC), supported by Police Service of Northern Ireland (PSNI), seized the cigarettes, worth an estimated £6 million in duty and taxes, on 4 November.
Officers searched two premises near Newry and found 11.5 million non-UK duty paid cigarettes.
They also seized a number of vehicles, fuel laundering equipment and 400 litres of illegal fuel.
Four men, aged between 23 and 33, were arrested and released on bail. Investigations into the seizure are continuing, the agency added.
“The trade in illicit cigarettes and tobacco damages funding for essential public services and undermines legitimate traders including small, independent shops that serve local communities,” Dermot Clarke, operational lead, fraud investigation service, HMRC, said.
“We continue to work closely with our partners to relentlessly pursue the determined minority who refuse to play by the rules.”
Superintendent Norman Haslett, district commander for Newry, Mourne and Down, added: “This is an incredibly significant seizure and shows that we are committed to working with our partners to keep communities safe in Northern Ireland.
“We remain resolute in our efforts to put those suspected of profiting from criminality before the courts.”