A member of An Garda Síochána who gave evidence before the Disclosures Tribunal has brought a High Court action aimed at stopping an internal garda investigation into alleged breaches of discipline by him.

Garda Keith Harrison, who denies the alleged misconduct, says the investigation has been brought on behalf of the Garda Commissioner following certain adverse comments made about the garda in an interim report by the tribunal chairman, Mr Justice Peter Charleton.

His lawyers argue the tribunal's comments cannot have any legal implications nor can they be relied upon by the Garda Commissioner to discipline Garda Harrison and the investigation should be prohibited.

Last November the Disclosures Tribunal rejected allegations made by Garda Harrison and his partner, Marissa Simms.

The couple made a number of allegations, including one that Ms Simms was compelled by gardaí to make a statement against him which led to a Tusla referral.

The Co Donegal-based garda also alleged he was the victim of a five-year intimidation campaign after arresting a fellow officer for drink driving in Athlone in 2009.

In an interim report, Mr Justice Charleton said all of Garda Harrison and Ms Simms allegations examined by the tribunal were "entirely without any validity."

The judge said he was exonerating persons with Tusla and An Garda Síochána who had been accused of wrongdoing.

Last July Garda Harrison was informed that a Garda Superintendent has been appointed to conduct an internal investigation into alleged breaches of discipline by him.

The misconduct alleged includes that that the adverse commentary by Mr Justice Charleton about Garda Harrison brought An Garda Síochána into disrepute and that allegations made by Garda Harrison in a protected disclosure were found to be false and entirely misleading.

It is also alleged that the motivation by Garda Harrison in making those allegations was malicious and vexatious and that his conduct in incidents outlined in evidence to the tribunal was unbecoming to a member of the Garda. 

Garda Harrison denies the allegations and his lawyers have called on the commissioner to end what he claims is an unlawful investigation, which the commissioner has failed to do.

In his action against the commissioner, Garda Harrison, represented by Mark Harty SC instructed by Kilfeather & Co Solicitors, seeks declarations and orders including an order quashing the decision to appoint an officer to investigate alleged breaches of discipline by the garda.

He also seeks declarations that the decision to appoint an investigating officer is unlawful and by seeking to place reliance on the findings of a tribunal of inquiry the commissioner has acted outside his jurisdiction and in breach of natural and constitutional justice. 

Counsel also told the court that it is Garda Harrison's case that by in seeking to discipline his client on the basis of what was contained in protective disclosures the commissioner is acting in breach of the 2014 Protective Disclosures Act. 

Permission to bring the action was granted, on an ex parte basis, by Mr Justice Seamus Noonan at the High Court. 

The judge made the matter returnable to a date later this month.