Gardai seized €500,000 worth of cannabis plants tday(Fri) in a remote are of Co. Donegal.
The plants, with sophisticated growing equipment, were found in a warehouse at Trummon, outside Laghey near Donegal town.
Two Chinese men, aged 34 and 24, were arrested and are being held at Ballyshannon Garda station.
The raid, with local detectives and the National Drugs Unit, was launched just before 12.30 pm yesterday.
Gardai had a court warrant for the search.
South Donegal Garda Supt Leo McGinn said: “This operation was being prepared for a couple of weeks.
“There is no doubt it was a highly sophisticated operation.”
Detectives are believed to have followed suspects for several days before the swoop was launched.