A man, arrested by police investigating allegations of ill-treatment of vulnerable patients at Muckamore Abbey Hospital, has been released pending a report to the Public Prosecution Service (PPS). It was the ninth arrest made by detectives investigating thousands of incidents of alleged physical and mental abuse at the Co Antrim facility.
The hospital treats patients with severe learning difficulties and mental health problems.
The 25-year-old was released on Tuesday evening.
In August the head of the Belfast Health Trust expressed "profound regret" after an independent review found leadership failings at the hospital.
A public inquiry is to be held.