Gardaí are questioning two men about the murder of Detective Adrian Donohoe five years ago.
The first, in his 20s, was arrested outside Wheatfield Prison in Dublin on Sunday.
While the second, in his 60s, was arrested in Dundalk last night.
Adrian Donohoe was shot dead in the line of duty during a raid on a Credit Union in Belurgan in Cavan in January 2013.
