Tánaiste Frances Fitzgerald has expressed her full confidence in Garda Commissioner Nóirín O'Sullivan following the latest whistleblower allegations. 

But the justice minister again refused to comment on the content of claims made by whistleblowers from within the force. 

"Do not ask me as minister charged with defending the principles of justice that are fundamental to society to set aside those principles, in this or any case," she told TDs in the Dáil this afternoon. 

"No findings of any wrongdoing of any kind have been made against the garda commissioner and under those circumstance she is entitled to our full confidence."

Minister Fitzgerald said the allegations are of the utmost seriousness, adding that Attorney General Máire Whelan is being consulted on how to proceed with a quick examination. 

Ms O'Sullivan yesterday denied being aware or involved in any whistleblower smear campaign.

It followed an Irish Examiner report that statements made by two senior gardaí alleged that senior garda management set out to destroy the character of a whistleblower within the force.

The paper said the disclosures detailed attempts to undermine the whistleblower by encouraging officers to attack his character, creating an intelligence file on him and monitoring his activities on the garda Pulse system.

Taoiseach Enda Kenny indicated yesterday that a judge could be appointed to examine the claims.

He also insisted he had "absolute confidence" in Nóirín O'Sullivan, following calls for her resignation by TD Clare Daly.

'Honourable man'

Earlier today, one of the whistleblowers at the centre of the scandal was described as a "decent, honourable man".

Retired detective sergeant Alan Bailey said the senior officer, who claims he was involved in alleged efforts to discredit a previous whistleblower, felt it was his duty to contact Minister for Justice Frances Fitzgerald.

"I would imagine he has come forward because he feels it is his duty as a serving member to highlight certain aspects of distasteful practice, if they are true," he told Newstalk Breakfast.

Mr Bailey added: "What saddens me about this is that if [the claims] are true, it means nothing has changed."

He told the programme that questions about the treatment of whistleblowers threatened to undermine the force’s credibility.

"It’s tearing the heart out of policing. It’s casting doubt on everything we ever did or will do," he said.

"It’s casting huge doubt on our credibility as a police force."