THE senior officer who led the garda watchdog's investigation into allegations of collusion between detectives and a drug trafficker is suing the Garda Commissioner and the Justice Minister.
James Costello, who retired as a garda detective to join the Garda Siochana Ombudsman Commission (GSOC), has begun High Court proceedings against his former employers over pension entitlements.
He was the officer in charge of a four-year investigation into allegations of an improper relationship between a number of senior gardai and an informant, international drug trafficker Kieran Boylan.
According to the High Court diary, papers in the action were first lodged in 2007 but so far no date has been set for hearing the action.
It is understood that the dispute arose when Mr Costello, a long- serving detective sergeant, resigned from the force in 1998. He took up a post as a senior investigator with the International Criminal Tribunal for the former Yugoslavia in The Hague.
Gardai are required to resign when they take sabbaticals with international war crime tribunals, but are entitled to return to their jobs at the same rank when their foreign contracts have ended.
Mr Costello rejoined the gardai in 2003 and was posted as a detective sergeant to Fitzgibbon Street station in Dublin, and later as a senior investigator with the Criminal Assets Bureau.
He was one of five senior garda detectives who retired from the force to join the Garda Siochana Ombudsman Commission (GSOC) as investigators when it was established in 2007.
It is understood Mr Costello will claim that his garda pension should also include the five-year break in his service, and that he paid his pension contributions for that period in full upon his return to Ireland.
A spokesman for GSOC said that he would not comment on the "private circumstances of any of its staff" and said the case had no bearing on Mr Costello's day-to-day interaction with An Garda Siochana.