In July this year, HSE CEO Bernard Gloster requested safeguarding expert Jackie McIlroy to review a report by the National Independent Review Panel (NIRP) into the rape of the resident known as "Emily".
Ms McIlroy was also asked to assess the work of a separate safeguarding review team that was tasked with examining 79 residents' files by November 2021.
In order to meet that timeframe, the safeguarding team reviewed the files of 32 residents in this group which resulted in a referral to An Garda Síochána outlining safeguarding concerns in the case of 21 of these 32 residents' files.
The HSE has said that it "absolutely accepts" Ms McIlroy’s view on this, and her recommendation that a further investigation of residents’ files is undertaken to cover the period of Mr Z’s employment.
Ms McIlroy has advised the HSE that it is highly probable that if a further examination of residents’ records is conducted, further indicators of possible harm will be found.
The HSE has pointed out that the staff member known as "Mr Z" worked at the unit for 16 years, and over that period of time several hundred residents were cared for there.
"We are currently developing a process to undertake this review and intend to write to the families of all residents at this unit during the period of Mr Z’s employment. We intend to do this in collaboration with residents or where appropriate their next of kin", according to Bernard Gloster.
Mr Gloster said the HSE recognised how "difficult and distressing this will be for families" adding that the HSE is "committed to undertaking this process as sensitively and compassionately as possible, fully respecting the wishes of individual families".
He added: "We note Ms McIlroy statement that the findings from any further examination of records, although likely to be inconclusive, has the potential to have a significant impact on families and their wellbeing, therefore we will ensure that we work closely with families throughout this process and provide them with any necessary supports."
The Irish Association of Social Workers welcomed Jackie McIlroy's report, saying it fully supports her recommendations.
The IASW said the report vindicates the work of the safeguarding social work team in the Emily case.
"Expert social work advice was ignored in the Brandon case and now again in the Emily case. Adults at risk of abuse are paying the price for poor oversight of safeguarding at both local and national level in the HSE," the group said.
It added that it was now up to the HSE to "explain how within current structures, it will prevent managers with less expertise overriding expert social work recommendations".
IASW said it welcomes HSE chief Bernard Gloster's "genuine commitment to reviewing safeguarding structures".