The Health Service Executive said it is investigating the sudden death of a woman at St Senan's Psychiatric Hospital in Enniscorthy, Co Wexford last Friday.
While the HSE does not comment on individual cases, it is understood that the matter relates to the death of a woman from Co Wexford who was in her 40s.
The woman had been admitted to the hospital earlier in the week.
Foul play is not suspected and it is understood the investigation will focus on systems in place within the hospital when a person is admitted.
