The 'Grace' abuse case has been described as "the greatest scandal of our time" during a Dáil debate on the interim reports by the State Commission of Investigation into what happened.

The commission is probing the 20 years of neglect of Grace, an intellectually disabled woman placed in a foster home in the south-east of the country.

The two interim reports, published in late September, found "systemic failings" by officials in the handling of Grace's case.

In the Dáil today, Fianna Fáil TD John McGuinness outlined, in graphic detail, instances where he believed people should have "spoken up for her".

Deputy McGuinness, who helped to expose the Grace case in 2016, was strongly critical of the gardaí, the Health Service Executive and Department of Health.

He criticised the Taoiseach and Minister for Health for not attending today's debate.

John McGuinness also described the case as "the greatest scandal of our time".

He told the Dáil that a whistle-blower lost her job because she went to TDs about the case.

He said that a subsequent settlement in the High Court, meant that details of what the whistle-blower saw would never be revealed.

However, Mr McGuinness also said that there was already enough information in the public domain to prove that Grace had been failed by the state.

He accused HSE officials of telling "blatant lies" when they appeared before the Public Accounts Committee a number of years ago.

"They should be called back in and they should be put through the ringer in relation to the misinformation that they gave this house," he said.

The Ceann Comhairle told the Dáil that contributions he witnessed in the chamber relating to the Grace case today would have left anyone with a heart "deeply moved".

Seán Ó Fearghaíl said the debate on the two interim reports from the Commission of Investigation into the Grace case was like nothing he had heard before.

The commission has been granted one final extension to allow it to conclude its work by July 2022.