I made conscious decision not to interfere, Frances Fitzgerald tells tribunal

The DPP had then recommended no prosecution, saying there was no evidence of a crime after a garda investigation was completed.

The Charleton Tribunal is examining whether unjustified grounds were inappropriately relied upon by the former garda commissioner Nóirín O'Sullivan to discredit Sgt McCabe at the O'Higgins Commission of Investigation.

The commission, which sat in private in 2015, investigated complaints made by Sgt McCabe about certain policing matters and about serious allegations against senior officers including then Garda Commissioner, Martin Callinan.

"I made a conscious decision obviously not to interfere in the commission in any way because I would have considered it inappropriate, and I took a conscious decision that Judge O'Higgins would deal with whatever issues, as I expected he would at the commission," Ms Fitzgerald told the tribunal.

Ms Fitzgerald said that at the time she was doing lots of other work in relation to how whistleblowers were dealt with, including the Protected Disclosures Act, allowing garda officers to approach GSOC directly, and setting up the Policing Authority.

Ms Fitzgerald was asked if she had spoken to her departmental officials or special advisors about the information she received, and said she had not.

"Imagine if I had, I would have been accused of interfering with the legal strategy of a party to the commission," Ms Fitzgerald said.

She also said that if she had asked departmental lawyers to talk to the garda legal team, that would also be considered interfering with the commission and she did not consider speaking to the garda commissioner personally.

Ms Fitzgerald said it was clear from the information she received that there wasn't a role for the Attorney General or the minister at the commission.

Ms Fitzgerald said there was a separation between department and commission, which was "observed in a very careful and consistent manner."

Ms Fitzgerald said she did not learn that deputy secretary Ken O'Leary had spoken to Commissioner O'Sullivan about her legal strategy the same weekend Ms Fitzgerald was informed until statements were given to the tribunal.

"If I had interfered with the O'Higgins commission in any way I would be answering different questions," Ms Fitzgerald said.

She said it would be inappropriate for her as a Minister, and "the day of political interference or anything like that was well gone as far as I was concerned."

Ms Fitzgerald said she met with Sgt McCabe after he contacted her in October 2014 "to see first-hand what his experience had been."

After the meeting, she received emails and updates from the sergeant, and in February 2015 she wrote to the garda commissioner asking about concerns Sgt McCabe was raising about his workplace situation.

The minister received assurances from the commissioner that she was working with Sgt McCabe on workplace issues, and was aware of her duties under Protected Disclosures Act.

Sgt McCabe later wrote to the minister to thank her for her efforts, saying "It's great to be able to say for the first time in years that I am happy going to work."

Ms Fitzgerald will continue giving evidence at the tribunal tomorrow.