It is understood that a serious assault occurred in Eist Linn Child and Adolescent In-patient Unit Bessborough, Blackrock, Cork, on January 16.
Gardaí have confirmed that they are investigating an alleged incident that is reported to have occurred.
The 16-bed Eist Linn facility is one of four national in-patient child and adolescent services, and supports the operation of eight Cork community mental health teams for CAMHS (Child and Adolescent Mental Health Services).
Last month, SIPTU representatives wrote to management of the Eist Linn unit regarding “serious staffing issues” that are creating an “unacceptable” situation whereby staff are “attempting to deliver a service with only 58% of nursing posts filled”.
The union called for a “comprehensive plan” to be put in place to address the level of nursing vacancies in the immediate term.