Detectives from the Garda National Drugs Unit are questioning a 27-year-old Russian man in Wexford following the seizure of more than 113,000 ecstasy tablets estimated to be worth more than €1.1m.
Officers from Revenue's Customs Service found the drugs hidden in a sophisticated concealment in the bumper of a Saab 900 car which arrived at Rosslare on the car ferry from Cherbourg last night.
Gardai believe the seizure, which was masked with coffee, is a major blow to a Lithuanian drug dealing gang, some of whom are based in Ireland.
The arrested man is now being questioned in Wexford by detectives from the Garda National Drugs Unit with the aid of an interpreter.
Forensic and fingerprint tests are now being carried out on the car and the drugs.
Gardaí are liaising with Europol as part of their investigation into the activities of those believed to be behind the shipment.