Three men and a woman have been arrested after the discovery of a cannabis grow-house in Co. Laois.
Officers from the Garda National Drugs Unit uncovered the factory at a warehouse in Kyletalesha outside Portlaoise, with 1,500 plants and a sophisticated lighting and irrigation system.
The plants have an estimated street value of €600,000, pending further analysis.
Gardaí made the discovery after conducting a number of searches in the Laois-Offaly area as part of Operation Nitrogen.
Three men and one woman, aged between 35 to 42, were arrested at scene and are being held at Tullamore Garda Station under section 2 of the Drug Trafficking Act.