Diary records show that former garda commissioner Nóirín O'Sullivan was in London on the day a garda HR executive says she attended a meeting, after which he was told they were “going after” whistleblower Sgt Maurice McCabe.

Former justice minister Frances Fitzgerald was shown an email and a print-out outlining a challenge by legal representatives of Garda Commissioner Noirin O'Sullivan to the credibility of garda whistleblower Sgt Maurice McCabe, the Charleton tribunal has heard.

An independent review initially considered adding an historic complaint against whistleblower Sgt Maurice McCabe to the terms of reference of the O'Higgins commission of investigation, but decided not to after reviewing the garda investigation files.

Former Garda Commissioner Nóirín O'Sullivan has told the Charleton Tribunal that she had done nothing that would threaten the role of garda whistleblower Sgt Maurice McCabe.

A garda witness has told the Charleton Tribunal that former Commissioner Nóirín O'Sullivan did not contribute to a document which outlined legal instructions to challenge whistleblower Maurice McCabe's motivation.