Tánaiste Frances Fitzgerald received three emails advising her of the legal strategy being used by the former Garda commissioner Nóirín O’Sullivan against Garda whistleblower Sgt Maurice McCabe.

Ms Fitzgerald has been under intense political pressure in recent days to outline her knowledge of the approach taken by Ms O’Sullivan at the O’Higgins commission, which was examining allegations of Garda malpractice.

Up until last week the Tánaiste had insisted she did not become aware of the strategy, which sought to undermine Sgt McCabe’s motivation and credibility, until it was made public in May 2016.

However, correspondence released by the Department of Justice on Monday night showed how Ms Fitzgerald was contacted on two separate dates in 2015 about the issue.

An email was sent to the Tánaiste on May 15th and two separate emails were sent to her on July 4th.

The May 15th email was responded to on May 25th by the Tánaiste’s private secretary, who confirmed she had “noted” the contents of the correspondence outlining the legal strategy being pursued.

Two emails were sent to Ms Fitzgerald in a fortnight from Department of Justice deputy secretary Ken O’Leary, who advised her of a telephone call he had with Ms O’Sullivan.

Email threads discovered in search of records

The commissioner had informed Mr O’Leary that media queries had been submitted to the Garda press office about the “aggressive” approach being adopted by her legal team at the commission of inquiry.

Mr O’Leary went on to advise Ms Fitzgerald how she should respond if questioned about this. She was told to outline her belief that Sgt McCabe was a valued member of the force and that this was also the view of Ms O’Sullivan.

Ms Fitzgerald was also instructed to say Mr McCabe was entitled to confidentiality in his dealings with the Garda authorities and therefore it would not be appropriate for her to comment.

Mr O’Leary’s email also advises Ms Fitzgerald to state that the approach taken by Ms O’Sullivan is a matter for the commission and it would “be wrong for anyone to make public comment which might interfere with or attempt to influence those proceedings in an way”.

Trawl of documents

This email was also sent to Ms Fitzgerald’s two special advisers at the time, the secretary general of the Department of Justice Noel Waters and Ms Fitzgerald’s private secretary among others. The timing of the email was 8.05pm. At 8.20pm, Mr O’Leary forwarded the email to Ms O’Sullivan for her information.

At 9.15pm the former Garda commissioner responded to Mr O’Leary with the Garda press office’s response to the press queries. Fifteen minutes later, at 9.30pm, Mr O’Leary wrote to the Tánaiste offering her further advice on how to respond.

On this occasion, he said “the conduct of the Garda case at the commission is entirely a matter for the Garda Commissioner on the basis of the legal advice given to her”.

The emails were unearthed as part of a trawl of documents in the Department of Justice ordered by Taoiseach Leo Varadkar.

Such correspondence should have been forwarded to the Charleton tribunal, which is examining this matter.

Mr Waters compiled a report for Ms Fitzgerald, Minister for Justice Charlie Flanagan and secretary general of the Department of the Taoiseach Martin Fraser. It was sent to all three last Friday. However, it did not include all details of correspondence but did include the two emails cited.

Mr Waters said an instruction had now been issued to all officials to notify him of any further records and to deliver them to the Charleton tribunal “without delay”.

The tribunal has written to all the officials in the Department of Justice who received the emails seeking statements.