Tusla, the Child and Family Agency, is facing legal action after it emerged it sent a file containing false allegations of child sex abuse against a Garda whistleblower to An Garda Síochána.

Sgt Maurice McCabe, whose treatment by Garda management is being investigated by a commission of inquiry, is to take legal action against Tusla and has sought a full apology.

A Tusla spokeswoman declined to comment on individual cases but it is understood to be willing to offer Sgt McCabe an apology.

It has emerged that members at the highest level of the force were aware of the claims made against the Garda sergeant but never informed him.

A commission of investigation headed by Supreme Court judge Peter Charleton has been established to look into claims that senior gardaí including Garda Commissioner Nóirín O’Sullivan orchestrated a smear campaign against Sgt McCabe in an attempt to discredit him.

Freedom of Information documents released to the whistleblower showed Tusla received a complaint from a counsellor about Sgt McCabe in August 2013 and passed the claims to the Garda.

Never questioned

No contact was made with the sergeant himself and he was never questioned in connection with the claims.

In May 2014 Tusla admitted the file should not have been created and was a clerical error on their part.

The file included details of Sgt McCabe’s family including his wife and children and is understood to have remained active until recently.

In June 2014 it is alleged Ms O’Sullivan met the superintendent in Sgt McCabe’s district in Bailieborough, Co Cavan to discuss the claims.

However, a Garda spokesman strongly rejected the claim, insisting no meeting ever took place.

The allegations place further pressure on Ms O’Sullivan to outline why she did not make Sgt McCabe aware of the claims or inform him when the file was found to be an error.

The Garda spokesman declined to comment further.

Disciplined

Some years earlier, she had made a separate, less serious allegation against Sgt McCabe, which had been investigated and dismissed by the DPP.

Tusla sought to correct its files, but in late 2015, a Tusla investigating officer wrote to Sgt McCabe repeating the allegation and requesting an interview. This was the first he knew of the allegations.

Five months later, Tusla confirmed to Sgt McCabe that there was in fact no such allegation against him.

Meanwhile, Tánaiste Frances Fitzgerald has confirmed Ministers are to be included in the commission of investigation’s terms of reference.

She has agreed to widen the scope of the inquiry to include former and current Ministers to assess their level of contact with former commissioner Martin Callinan and Ms O’Sullivan.

A spokesman for Ms Fitzgerald said the details would be discussed at Cabinet next week.

Ms O’Sullivan faced renewed calls to stand aside yesterday from Labour, Sinn Féin and Independent TDs.

However, Taoiseach Enda Kenny and the Tánaiste said she retained their full support.