Garda whistleblower told detective superintendent he would 'take down' Nóirín O'Sullivan, Disclosures Tribunal hears

A Garda whistleblower told a detective superintendent he was going to "take down" Garda Commissioner Nóirín O'Sullivan and wage "all-out attack" on management, a tribunal has heard.

Gda Nicholas Keogh is giving evidence at the Disclosures Tribunal where counsel for An Garda Síochána are cross-examining him.