Nearly 700 complaints were made to the Health Information and Quality Authority (HIQA) last year over the care of vulnerable adults in Irish nursing homes.
The claims which were released under the Freedom of Information Act to Fine Gael Deputy Fergus O'Dowd included allegations of sexual assault, financial abuse, and general lack of care and compassion.
HIQA says it does not have a remit to investigate individual complaints but where appropriate, information is passed on to Gardaí and other relevant bodies.
However, Deputy O’Dowd said there needs to be further reassurance about how complaints are dealt with and how information is shared.
He said that what "concerned" him greatly was not only the number of complaints that were made but what happened and how they were dealt with.
"I couldn't point out how they were dealt with clearly. My Freedom of Information request was rejected.
"But I wanted to find out what actions were taken and what the outcomes were. I think the public, and not just me, are entitled to that."