Almost 60 staff have now been suspended from the scandal-hit Muckamore Abbey Hospital.
The Irish News has learned that the latest precautionary suspensions took place in recent months - there were just over 40 at the beginning of the year - and relate to the massive PSNI investigation into alleged abuse of vulnerable patients.
A pressure group made up of relatives campaigning for a public inquiry last night said they were unaware the extra suspensions had taken place.
The Belfast health trust confirmed a total of 59 employees are currently placed on "precautionary suspension", with the latest carried out on June 9.
It is understood that 39 of the suspended staff remain employees of the Co Antrim hospital. All remain on full pay.
Minutes of a Department of Health-led 'assurances group' meeting last week also revealed that concerns about the actions of a further 47 Muckamore staff meant they "have been placed on supervision". Of these, 15 are "no longer working in the hospital".
The minutes, seen by The Irish News, state that trust officials are "liaising with the current employers of these (15) staff to ensure they are aware of their supervisory arrangements".
Glynn Brown, who heads up the Action for Muckamore pressure group, and first raised the alarm three years ago after his non-verbal autistic son, Aaron, was allegedly assaulted while being cared for in the hospital's Psychiatric Intensive Care Unit (PICU), said the need for an inquiry is more pressing than ever.
"The latest suspensions and staff being supervised are news to me. We were always told that we'd be kept in the loop but once again we haven't," he said.
"I'm also annoyed with our politicians. We keep hearing about collective responsibility but where is it when it comes to Muckamore? This scandal is getting bigger by the month, it's time for proper, resolute action.
"We also have concerns about the suspended staff who are no longer working in Muckamore Abbey Hospital. In what setting are they working? Are all their employers aware of their situation and allegations?"
A recruitment programme is ongoing and has attracted eight new 'band five' nurses at Muckamore.
However, at last week's meeting it was confirmed that "40 per cent of the nursing workforce are long term agency staff".
A total of seven people have now been arrested in relation to the police investigation, which is the biggest adult safeguarding case of its kind in Northern Ireland with 1,500 suspected crimes relating to one ward alone.
Much of the evidence relates to 300,000 hours of CCTV footage reportedly showing abuse.
Files were submitted by detectives to the Public Prosecution Service in April.
