A man in his early 50s who was arrested for suspected conspiracy to pervert the course of justice has been released without charge, the Garda Press Office has said.
The arrest, under section 4 Criminal Justice act 1984, was linked to investigations by personnel attached to the Garda National Bureau of Criminal Investigation into alleged wrong-doing or corruption involving Garda personnel in the Southern Region.
The man was detained at a Garda station in Co Tipperary.
In May a garda, an inspector and a superintendent were detained as part of a wider inquiry into alleged unusual relationships between a small number of officers and a crime gang in the Munster region.
It is understood the man arrested on Thursday is not a member of the force and is not a member of the criminal gang that it is feared may have been receiving confidential Garda information.
The investigation is probing whether he may have played a role in the alleged conveying of the information to the criminal gang.
While the three arrests in May were linked, only the member of superintendent rank was questioned on suspicion of leaking information.
The senior officer was arrested under the provisions of section 62 of the Garda Síochána Act, 2005, which relates to Garda members disclosing information.
The inspector was questioned under the Misuse of Drugs Act, 1977-84.
The member of garda rank was questioned about an alleged conspiracy to pervert the course of justice.
The investigation is trying to establish whether the criminal gang had been assisted by Garda members. The inquiry has been ongoing for some time and several officers have been suspects for a period of time.
In May, the local Garda division was not told of a planned Garda operation by a Dublin specialist unit against the criminal gang over concerns the news might leak.
