A former politician is being questioned by detectives on suspicion of conspiracy to murder.
Gardaí said the man in his 30s was arrested in Cork this morning and is being quizzed at a station in the county.
He can be held for up to a week under Section 50 of the Criminal Justice Act.
It is understood detectives are investigating an allegation of a plot to kill three people and were acting on information when they made the arrest.
