A former Department of Justice official has acknowledged the Department was working 'hand in glove' with Nóirín O'Sullivan in the aftermath of the O'Higgins Commission because, he said, it was in the public interest.

Ken O'Leary, who was deputy secretary general at the Department during the O'Higgins Commission of Investigation in 2015, is giving evidence at the Disclosures Tribunal.

The Tribunal is examining whether or not former garda commissioner O'Sullivan inappropriately relied on unjustified grounds to discredit whistleblower Sergeant Maurice McCabe at the O'Higgins Commission.

Mr O'Leary was asked about a letter he was involved in drafting for Ms O'Sullivan to send to the Department and then minister for justice Frances Fitzgerald in the aftermath of the O'Higgins Commission in 2016.

He said he knew the exchange of letters might look a bit odd, but he said in reality he and his colleagues in the Department were trying to bring the controversy to an end.

The Tribunal heard Mr O'Leary did up a draft of a letter which was shared with others in the Department for their consideration, including the Acting General Secretary Noel Waters.

Counsel for the Tribunal, Patrick Marrinan, asked Mr O'Leary if the Department was working 'hand in glove' with the former garda commissioner.

Mr O'Leary acknowledged that was the case but said it was for a very good reason.

Mr O'Leary said there was nothing in the O'Higgins Commission report that called into question the position of the garda commissioner.

He said the Department's view was that the public interest was not going to be served by the Garda Commissioner's position being put in jeopardy.

Mr O'Leary said the phrase 'hand in glove' was a bit pejorative, but he said the Department was working closely with Commissioner O'Sullivan.

He said it was not all friends helping each other but it was the Department's clear view of where he and his colleagues thought the public interest lay.

Ms O'Sullivan told the Tribunal during her evidence last week that the final version of this letter was her letter expressing her view.

Mr O'Leary was also asked about two phone calls between him and Ms O'Sullivan on the 15 May 2015, the day a dispute arose at the O'Higgins Commission about the Garda legal strategy.

He said he had told Ms O'Sullivan that the department could not become in any way involved in what approach she was taking at the Commission.

He said she asked him about other issues that she might need to be mindful of.

Mr O'Leary said this was on a colleague-to-colleague basis and he said he had mentioned obvious issues including the sensitivities in relation to the position of Sgt McCabe.

Mr O'Leary also said that during one of the calls he understood Ms O'Sullivan was also on another call to the Garda representative at the O'Higgins Commission, Chief Supt Fergus Healy.

He said he was slightly concerned about this from his point of view of not becoming involved in specifics of what was going on at the O'Higgins Commission.

Counsel for the Tribunal Patrick Marrinan pointed out that there had been a chain of emails arising from contact between the Attorney General's Office and the Department in relation to the row that had emerged at the O'Higgins Commission on 15 May 2015, but there was no record of Mr O'Leary's calls with Ms O'Sullivan the same day.

Mr O'Leary was also asked about a conversation between him and another Department official, Michael Flahive, who had received a call from the Attorney General's office raising the issue of the Garda legal strategy at the O'Higgins Commission.

He told the Tribunal that they agreed that Mr Flahive should email the minister setting out what had happened.

Mr O'Leary said he believed this was the appropriate way for the minister to be informed of the matter, through the contact with the Attorney General's Office, and he said he did not separately inform the minister.

Lawyer for the Garda Commissioner, Conor Dignam, asked whether Mr O'Leary could be mistaken that a second phone call took place with Ms O'Sullivan on the afternoon of Friday 15 May 2015.

Mr O'Leary said his best recollection was that there were two calls.

Mr Dignam said a search of all Ms O'Sullivan's devices and landlines only disclosed one phone call.

A laywer from the Attorney General’s Office has told the tribunal that he was concerned that an allegation made against Sgt McCabe which was dismissed by the Director of Public Prosecutions would be ventilated at the OHiggins Commission.

In a statement to the tribunal, Michael Dreelan said he was informed by Annmarie Ryan of the Chief State Solicitor's Office in May 2015 that issues relating to the investigation of the 'Ms D' allegation were being raised at the O'Higgins Commission as part of a Garda legal approach to question Sgt McCabe’s motivation.

He said when he heard about the situation he felt there was a need to take a pause.

The tribunal heard that the Attorney General’s Office was not giving direction in relation to any legal strategy by the Garda legal team.

However, Mr Dreelan said when he was informed of the situation he was concerned that all appropriate parties were aware of the approach being taken to be able to make any relevant observations.

In his statement, Mr Dreelan said he thought the Attorney General should be personally aware of the situation lest she wish to make any intervention.

Minister advised of 'significant development'

Mr Flahive said it would not have been proper or possible for the minister to intervene in a row about the questioning of Sgt McCabe.

He said that when he was told of the row at the O'Higgins Commission, he felt he had to advise the minister and senior colleagues about it as it was a "significant development".

However, he said he was clear in his mind that there was no role for the minister in it.

On 15 May 2015, Mr Flahive received a phone call from Richard Barrett of the Attorney General’s Office informing him of the row at the O'Higgins Commission.

Mr Flahive said he also spoke to his colleague, Mr O'Leary who had spoken by phone to Ms O'Sullivan.

Mr Flahive sent an email to several officials in the Department about the call.  The emergence of this email in November led to a controversy which eventually resulted in Frances Fitzgerald resigning as minister for justice.

Counsel for the Tribunal, Kathleen Leader, asked whether there was any sense in the Department that it now had a problem to resolve given that it had the information from two sources that something had happened at the O'Higgins Commission which was sensitive.

Mr Flahive said he had a sense that there was a problem, but it would not have been proper or possible for the Minister to intervene.

He also said he did not believe it would have been appropriate for the Minister to have asked or challenged the Garda Commissioner about the legal strategy.

He said the system was in place to handle the issue as Sgt McCabe's counsel had objected to the line of questioning at the O'Higgins Commission.

Questioned by the lawyer for the Garda Commissioner, Mr Dignam, Mr Flahive agreed that his email contained third or fourth hand information.

Mr Flahive was also asked about the consideration given to include the Garda investigation into the Ms D allegation in the O'Higgins Commission.

He said counsel for the Independent review Mechanism advised against its inclusion.

Mr Flahive also said he thought it was "problematical" and he said it could have made get Sgt McCabe feel victimised rather than vindicated.