Ecstasy tablets worth u £150,000 were seized and one person arrested by the police in Coleraine, Co Antrim, yesterday.
Some 15,000 tablets were recovered in a house in the Waterside area of the town by RUC Drug Squad officers. They were supported by a mobile support unit which specialises in search techniques.
Chief Insp Nigel Kyle, from Coleraine station, said the haul was one of the biggest seizures of ecstasy tablets in the north-west area and was "a great relief to police to have such a significant amount of drugs removed from the streets".
The arrest follows a series of raids in 16 addresses in Ballymena last Wednesday. A small quantity of drugs, cash and equipment were seized during those raids, which Insp Kyle said were not connected to yesterday's haul.
Seven men and one woman were remanded in custody for a week after they appeared in court in Ballymena, Co Antrim, last Thursday, on drugs charges