More medical staff have been suspended or moved to other duties as part of an inquiry into patient care at a mental health ward in north Wales.
Concerns about care at the Tawel Fan ward at Glan Clwyd Hospital in Denbighshire were raised last December.
Eight nurses have since been suspended and four have been moved to other duties, while two doctors are working under restrictions.
The ward closed after the allegations were made.
A spokesperson for Betsi Cadwaladr University Health Board (BCUHB) said the Nursing and Midwifery Council and General Medical Council had been informed.
The health board asked North Wales Police to investigate after it was notified of what it called "deeply disturbing" allegations in December 2013.
The publication of an independent report commissioned by BCUHB into the matter has been put on hold while the police inquiry continues.
Last week, issues surrounding the Tawel Fan ward became a target of criticism from the Conservatives and the Daily Mail newspaper on Labour's record running the health service in Wales.
The attacks prompted the Welsh Health Minister Mark Drakeford to write to his UK counterpart, Jeremy Hunt, stating that the NHS in Wales "will not be the victim of any Conservative Party ploy to drag its reputation through the mud for entirely partisan political purposes".