The Garda Commissioner is facing calls this evening to say whether she knew her predecessor was briefing against Sergeant Maurice McCabe.

Noirin O'Sullivan was the Deputy Commissioner under Martin Callinan, when he approached the chairman of the Public Accounts Committee to brief against the whistleblower.

John McGuinness says he met Martin Callinan in 2014, just before the Garda whistleblower Maurice McCabe attended a hearing at the committee.

He says Martin Callinan told him that Maurice McCabe was "not to be trusted" - but did not reveal the meeting until last week.

McGuinness has also been criticised over his failure to reveal the meeting before now.

Speaking on the Last Word, Sinn Féin's Mary Lou McDonald says the current Commissioner also has questions to answer: