A former investigator with the Garda Ombudsman Commission who attended a party in Gerard Hutch's home after Mr Hutch was found not guilty of murder will not be prosecuted.
Gardaí began an investigation into the suspected leak of confidential information to the Hutch organised crime group after it emerged the investigator had attended the party in April 2023.
The party was organised to celebrate Mr Hutch's acquittal of the murder of David Byrne and his release from custody after 20 months in prison on remand.
The Special Criminal Court found him to be the figurehead of the Hutch organised crime group who had control of the firearms used in the murder.
The GSOC investigator served as a police officer in another country outside Europe before joining the Garda Ombudsman and coming to Dublin.
He rented a room in a house near where a relative of Mr Hutch was living. He resigned from his position at GSOC when informed he was to be suspended.
The man, who is in his 60s, was arrested and questioned by detectives from the National Bureau of Criminal Investigation and subsequently released without charge.
A file was sent to the Director of Public Prosecutions who has decided that no prosecution should take place.
Garda Headquarters confirmed the DPP's decision and said it had no comment on the matter
Fiosrú, which replaced GSOC, has been contacted for comment.
It launched an internal investigation into the matter, which was discontinued when the investigator resigned.
The investigator worked with the Garda Ombudsman for five years and has since left the country.
In a statement, Fiosrú said: "In April 2023, GSOC immediately opened an internal investigation after becoming aware of a potential conflict of interest involving a staff member.
"The officer resigned within days of GSOC opening its investigation.
"In the same week in April 2023, GSOC also referred this matter to An Garda Síochána."
