The Health Information and Quality Authority has expressed "significant concern" over children living in unregulated special accommodation arrangements.
The regulator tracked the demand for these services over the past ten years.
It noted the significant shortage of appropriate residential and foster placements for children who require care.
It means some children are being accommodated in "inappropriate arrangements" for lengthy periods, according to a report published by HIQA this morning.
It states "an urgent need" to build additional capacity within children’s alternative care services to meet specific needs.
"The number of statutory children’s residential services has not altered significantly over the years, and at the end of 2023, there were 37 statutory children’s residential centres," according to the report.
It continued: "Tusla planned to open some new statutory residential services in 2024 and two such centres became operational during 2024. Despite, this the number of Children's Residential Centres has remained the same, as other centres have closed."
During the summer, the Child Law Project reported that multiple judges were "in despair" over the system of care for children in Ireland.
One High Court judge described the lack of special care beds as "a tsunami about to reach shore and nothing is being done".
In its ten-year review, HIQA also found that many children were not allocated social workers or else experienced multiple changes in social workers over short periods of time.
While Tusla has used social care staff to mitigate the risk associated with social work vacancies, vacancies have persisted in many services, according to the report.
There has also been a lack of suitable foster care and residential care placements for children requiring admission to care.
Lack of placements has led some children being unable to move on from some services when ready to do so.
Among the significant changes in the last ten years noted by HIQA are family structures, the complex needs of children, the impact of a pandemic on children and families, increases in population, cultural changes and unforeseen world events such as the impact of war in Ukraine and the increase in numbers of unaccompanied minors.
These additional challenges, according to the watchdog, together with gaps in staffing of children’s services and alternative care placements, have impacted the "timeliness and quality" of service received by some children in care and children availing of child protection and welfare services.
HIQA's Head of Programme for Children's Services Eva Boyle said children as young as 10 years of age have been living in hotel rooms and rented accommodation on an emergency basis.
Speaking to RTÉ's Drivetime, she said the arrangements are both short-term and long-term and are not regulated, meaning HIQA cannot monitor them properly.
"We don't enter these these premises, but we have unsolicited information that would say that there are children under the age of 10 on occasions in these arrangements in hotel rooms or in rented accommodation," she said.
Ms Boyle said the use of agency staff means it is rare that a child would be assigned a consistent care worker.
"I suppose that would be similar to residential care but in residential care you would have a consistent team working with the child who would know the child, know their care plan and have focused work to do with the child," she said, adding that Tusla has a significant recruitment issue.
"It is crucially important that a young person and a child has a trusted adult that they can work with," she said.
"Children consistently down through the years say that they need one worker who's consistent who could they can trust, who they can tell their story to, who can work with them."
Number of referrals doubled in ten years - Tusla
Tusla has welcomed HIQA's findings, noting that the report states that overall safeguarding and child protection practices have improved, and children and young people are receiving nurturing and safe care.
In a statement, it said the number of referrals to the agency has doubled over the past ten years.
It has pointed out that efforts are being made to move young people from special emergency arrangements to regulated settings as soon as possible, once alternative placements become available.
In order to manage the increased demand for placements for separated children seeking international protection, Tusla has said that placement capacity has been increased and new accommodation centres for unaccompanied minors have been established.
CEO Kate Duggan said the Child and Family Agency is "committed to strengthening the recruitment of, support to and retention of foster carers and ultimately reduce overall placements in residential settings. Our foster carers are instrumental to the work we do, and we are actively recruiting foster carers from diverse backgrounds in communities across Ireland."
She noted that recruitment challenges are not only faced by Tusla but across the sector.
"Our key objective is to strengthen recruitment and retention of a multidisciplinary workforce to better meet the needs of children and young people and provide a more supportive environment for staff.", she said.
In the statement, Tusla welcomed the oversight provided by HIQA because it said it assisted the agency in ensuring good quality practices and appropriate services for children and families.
"We are aware that we have further work to do, and this process of improvement of the quality of our services set against high standards and regulation is an ongoing process."
