Irish health authorities' handling of allegations that a woman with intellectual disabilities was sexually abused while in a foster home are a "disgrace to us and our country", Irish Prime Minster Enda Kenny has said.
The woman was allegedly subjected to abuse over a number of years.
Two reports have been published into how the Health Service Executive (HSE) handled the claims.
The HSE has apologised for the failings in care.
It said disciplinary proceedings would begin immediately into staff implicated in the failings.
The woman, known only as Grace, was a resident in a foster home in the south-east of the Republic of Ireland.
She had evidence of bruising and showed signs of sexualised behaviour.
Grace stayed in the home for 14 years after an allegation of sex abuse was made in relation to another resident.
According to one of the reports, no one at the HSE looked into the reasons why she was not moved many years earlier.
Mr Kenny told the Dáil (Irish parliament) that "the very least" the chamber could do was apologise to Grace and her family.
He also said that the terms of reference for a commission of inquiry into abuse at a foster home in the south-east would be published next week.
Mary-Lou McDonald, Sinn Féin's deputy leader, asked who in the HSE had been held responsible and whether arrests had been made in the criminal investigation.
"It's not enough to produce shocking reports - we need accountability," said Ms McDonald.
Mr Kenny replied that it was a criminal matter for the Republic's police commissioner to give details about but added that the government had agreed to set up a commission of investigation that will hear evidence in private.
The taoiseach told the Dáil that the minister with responsibility for disabilities, Finian McGrath, would bring the investigation's terms of reference to the Irish cabinet next Tuesday.
An interim report is expected within three months.