Five people are today being questioned by gardaí following the discovery of separate cannabis grow houses in Co Louth and Co Laois.
A 43-year old man has been arrested after a cannabis grow operation was uncovered near the village of Collon. Up to 500 cannabis plants worth an estimated €250,000 were discovered at the house.
Elsewhere, three men and a woman are still held following a raid on a large-scale operation in Co Laois yesterday.
About 1,500 cannabis plants worth an estimated €600,000 were recovered during the raid on a house in Kyletalesha on the outskirts of Portlaoise at about 1am yesterday.
The raid was carried out by the national drugs unit assisted by local gardaí. They arrested two Irishmen and two Asians.
The four suspect, who are all in their 20s, are being held at Tullamore Garda station.
The latest raids comes just two weeks after the seizure of cannabis valued at €400,000 at a grow house near Portarlington, Co Laois.
A Vietnamese man and woman were charged in connection with the discovery.