Gardaí are questioning two men and a woman after cannabis worth around €520,000 was found growing in three houses in Roscommon and Longford this morning.
According to gardaí, an intelligence-driven search by officers took place at Lisacul, Castlerea, Co Roscommon; Strokestown, Co Roscommon; and Drumlish, Co Longford.
At Lisacul, cannabis plants and dried cannabis herb with a street value of €84,000 was seized and a man was arrested.
At Strokestown, cannabis plants and dried cannabis herb with a street value of €147,000 was seized, and a man was arrested. In Drumlish, cannabis plants and dried herb with a street value of €287,000 was seized, and a woman was arrested.
All values are subject to an analysis of the substances and plants, gardaí said.
The searches arose out of an investigation following the discovery of a cannabis plant cultivation factory in Castlerea in April 2008.
The three suspects are being held at Roscommon, Boyle and Longford Garda stations under Section 2 of the Drug Trafficking Act. All three are understood to be Vietnamese.
Gardaí at Castlerea were assisted by the Garda National Drugs Unit and the Garda National Immigration Bureau.
Elsewhere, three people were arrested in the North after a cannabis factory was found in Ballycastle, Co Antrim, yesterday.
During the planned search of the house in Marconi Park at 11.30am, the PSNI found a substantial number of cannabis plants and other drugs-related equipment.
Two men, aged 21 and 46, and a woman (44) were arrested.