The gardaí were arrested on Saturday morning and questioned about concocting a story in order to aid a fellow garda who is facing firearms charges.
The three were arrested as part of an ongoing internal garda inquiry ordered by Commissioner Pat Byrne into the force in Co Donegal.
The men served with a detective who is facing firearms charges.
The detective and the three men are also being investigated by the Morris Tribunal, which was set up to investigate alleged corruption among gardaí in Co Donegal and elsewhere.
The three gardaí are suspected of giving a false account of how a firearm was found, which supported the case put forward by the detective. They were questioned about false reports and wasting garda time by officers attached to Assistant Commissioner Kevin Carty’s investigation.
They were released without charge and the investigating team will now prepare a file for the DPP.
Eight officers have been arrested by the Carty inquiry to date and two have had charges brought against them.
One of the two, Sgt John Nicholson, was found guilty of issuing false expense claims to informer Bernard Conlon.
Conlon had conspired with gardaí in creating allegations against Mark McConnell, a nephew of Frank McBrearty Snr and Michael Peoples, an employee of Mr McBrearty.
The alleged harassment of the McBrearty family forms a central part of the Morris Tribunal.
Nicholson was given the probation act, while Conlon, a man of low intelligence, received a three-year suspended sentence.
Last week, the Morris Tribunal said its work would be delayed after Garda Commissioner Pat Byrne had “unfortunately” sought a two-week extension.
This is to allow Commissioner Byrne file an affidavit of discovery in response to an order from the tribunal to hand over intelligence documents relating to garda handling of informants in Donegal.