Three safeguarding concerns identified by HIQA inspectors in centres for people with disabilities were referred to the HSE's National Safeguarding Office last year.
Of these, one case was referred to gardaí and Tusla because of the nature of the concerns identified.
In an overview report on disability services for 2021, the Health Information and Quality Authority said improvement was needed in disability services' governance and management arrangements, to ensure people with disabilities received good quality care.
The report said the absence of specific safeguarding legislation placed limited obligations on providers and persons in charge to protect residents from abuse, to investigate and to take action where allegations had arisen.
The report noted a deterioration in the "overall effectiveness" of safeguarding in the sector.
The independent watchdog said this showed more work needed to be done to ensure protection of residents from abuse through statutory legislation.
In 2020, inspectors found 11.9% non-compliance in congregated settings around the protection of residents. In 2021, non-compliance in these settings rose to 16.1%.
There was also an increase of non-compliance in community-based settings but at a smaller level - from 6.2% in 2020 to 7.1% in 2021.
HIQA said the data for 2021 demonstrated "the significant difference" in the quality and effectiveness of safeguarding arrangements in congregated settings when compared to community-based settings.
Inspectors found that providers with good safeguarding arrangements last year, were "responsive to emerging issues" and continuously demonstrated the capacity and competence within their workforce and leadership arrangements to put suitable safeguarding plans in place.
In centres with good compliance levels, inspectors identified that staff were being supported to keep their safeguarding training up to date. They knew how to identify and report safeguarding concerns.
In these centres, residents who spoke to inspectors about safeguarding said they felt safe and knew who they could speak to if they did not feel safe or had been hurt.
Overall the report, published by HIQA this morning, showed that the majority of the 1,220 centres inspected in disability services provided a good standard of care and support.
However, inspectors found overall compliance levels across the sector deteriorated when compared with 2020. It should be noted however that there were also significantly more on-site inspections completed in 2021 compared to the previous year.
In 2020, the regulation relating to governance and management was reviewed in 72% of inspections compared to 95% in 2021, which also contributed to the variation.
Despite this, HIQA has expressed concern in the report about governance and management and oversight arrangements since the pandemic.
Chief Inspector of Social Service Carol Grogan has described the increase in non-compliance in this area as "a worrying development as poor governance and management can lead to an overall deterioration in the quality and safety of services".
In a statement, Deputy Chief Inspector of Social Services (Disability) Finbarr Colfer noted the negative impact that poor governance and management has had on the quality and safety of care and support for residents - impacting their quality of life.
"It is critical that providers re-establish effective governance and oversight to ensure that residents receive the quality of support that they are entitled to."
He also noted "significant variance" in the level of non-compliance in congregated settings compared to community-based settings.
"A higher number of congregated settings than in previous years required improvements to the overall quality and safety of the premises. Further work is required to ensure that the use and reliance on congregated or campus-based settings continues to be reduced," he said.
Speaking on RTÉ's News At One programme, Mr Colfer said that one of the principal findings of the report is that one in five centres needed to improve governance.
"Critically, what governance is about is somebody within the organisation who is not involved in the centre, going in looking to see if it is being run properly, are people's rights being upheld, are people safe in that centre?
He said that as a public health measure during the pandemic these visits stopped, adding that safeguarding or abuse issues can arise in any centre.
"We take it very, very seriously. On our inspections, we look at what arrangements are put in place to respond quickly, where providers haven't responded adequately, or where they haven't made their own referrals, we will make referrals to the National Safeguarding Office or as necessary to An Garda Síochána as well."