The PSNI has carried out eight searches in counties Antrim and Down in connection with an ongoing investigation into allegations of mental and physical abuse at Muckamore Abbey Hospital.
Items including mobile phones were seized.
The investigation was led by the PSNI's Public Protection Branch.
There have been 158 incidents reported to police regarding Muckamore and police continue to pursue all avenues.
Nineteen staff members, many of whom are nurses, have been suspended.
"This demonstrates our commitment to delivering a full and thorough investigation," Det Ch Insp Jill Duffie said.
"The safeguarding and protection of our most vulnerable is a priority for the Police Service of Northern Ireland. "
"We will continue to work through every report made to us to establish if criminal offences have been committed.
"We are very sensitive to the trauma and impact upon those families whose loved ones are at the centre of this complex investigation.
"From the outset we have been committed to working closely with them and will continue to keep them informed as much as we possibly can."
Earlier on Wednesday, it was revealed that a controversial seclusion room at a scandal-hit County Antrim hospital was used 745 times in 2015.
Figures revealed that, in that year, 21 patients were placed in the room at Muckamore Abbey Hospital at least once.
Last month, the hospital was the subject of a damning report that listed a series of catastrophic care failings that compromised many patients' lives.
The room was used to treat patients with aggressive behaviour, the Belfast Health Trust said.