Gardaí are assisting a PSNI investigation into allegations surrounding a number of deaths at Our Lady's Hospice in Harold's Cross in Dublin.
RTÉ News understands that a man who worked at the hospice in the 1990s presented himself at a police station in Northern Ireland two days ago and claimed he was involved in the deaths of up to six patients.
The man has been arrested and is being detained at Antrim Road Police Station in Belfast.
The PSNI subsequently contacted Garda Headquarters and the Deputy Commissioner Fachtna Murphy has assigned a team of detectives to investigate the case.
This evening the CEO of the hospice, Mo Flynn, confirmed that the person in question worked in St. Patrick's Unit of the Hospice as a care assistant for six months during 1998 and on pastoral placement for one month during 1997.
During those periods, she said, all deaths among patients in the unit had been expected as a result of natural causes and no queries about them had ever been raised.
She said hospice management were co-operating fully with the gardaí.
The garda detective team is comprised of officers from the National Bureau of Criminal Investigation and detectives from the south city.
They are travelling to Belfast to try to establish the facts surrounding the allegations.
The man has been interviewed by the PSNI but detectives are also making arrangements to have him psychologically assessed.