Gardai investigating allegations of abuse at a residential centre in Longford for people with disabilities are understood to have broadened their inquiries to take in a second facility.
A woman suspected of injuring a female resident at the Longford disability centre was arrested on Friday and later released without charge.
Detectives are understood to have sought patient records from a second residential facility where the woman had previously worked.
Informed sources have said detectives are examining the records for possible evidence of abuse or complaints of it.
The alleged abuse came to light last month after a GP was called out to treat a resident living in the centre.
The latest investigation is one of at least half-a-dozen criminal inquiries under way into alleged abuses of vulnerable residents of disability centres across the country, including Cork, Tipperary and Mayo.
According to one source, gardai are coming across "institutionalised" mindsets in which the use of physical and verbal abuse was in some places regarded as acceptable.
Hiqa's chief executive, Phelim Quinn, told the Sunday Independent last month that there were "human rights abuses" in some centres, that they were "stuck in the 1980s" and he also suggested that staff needed to be more accountable.
He said nurses and carers in some facilities had "lost sight" of the fact that certain practices were abusive.
"I think as a nurse myself I find it hard to believe that you could become accustomed or acclimatised to those sorts of practices," he said.
The health watchdog, Hiqa began regulating the services two years ago and has since published hundreds of damning inspection reports on centres that have failed to meet standards.
In a separate row, the nursing union has accused the Health Service Executive of trying to cut staff numbers at one of the worst-performing intellectual disability centres at a time when the health watchdog called for staffing to be urgently increased.
The "service improvement team" was sent to St Mary's in Drumcar, Co Louth after it had failed to meet the watchdog's basic standards.
The Irish Nursing and Midwives Organisation claims that the specialist team advised "reducing staffing and skill mix" at the centre.
However, in a subsequent and damning inspection, Hiqa advised the immediate recruitment of 45 staff in order for the centre to meet standards.
The union wants to the HSE to explain how its advice was so out of kilter and called for a review of practices.
In a letter to the HSE's director general, Tony O'Brien, the local INMO rep, Tony Fitzpatrick asked the HSE to instigate an investigation into how the service-improvement team "could seek reductions in staffing" while it was clear to Hiqa and the INMO that more staff were required.
But the HSE this weekend denied the charge stating: The service improvement team's work was "far broader than a narrow focus on skill mix and reduction on staff numbers and over 45 additional staff have been taken on in the centre over the past 12 months.
"The Service Improvement Team has at no time advised the management of this service to reduce staffing."
St Mary's in Drumcar has been criticised over its conditions, treatment of residents and the lack of leadership.
The most recent Hiqa inspection report found that residents were locked into a bungalow and left without supervision, while the nurse distributed medicines in another unit in the centre.
Staffing levels were too low and there was "an inappropriate skill mix" of staff.
Residents were assaulting themselves and each other in the absence of staff, and it found ineffective leadership, governance and management arrangements.