A mental health centre in Galway used money it was safeguarding for residents to fill a deficit in other residents' monies without permission, according to an inspection report published by the Mental Health Commission (MHC).
Under law, every centre has a duty to ensure that provision is made for the safe-keeping of all personal property and possessions.
Centres must also ensure that a record of each resident's personal property and possessions is maintained and available to the resident.
The MHC inspection team found some residents in the Galway centre were unaware that their money was being used for other purposes.
The MHC said taking advantage of residents in this way was "unacceptable" and a clear denial of basic human rights.
Inspectors imposed a "critical risk rating" which required the HSE to take specific actions and provide assurances that residents' property and possessions were safe.
It also called for appropriate oversight and review mechanisms to be put in place to monitor the finances of all residents in the centre.
The MHC said it had since been provided with assurances of improved arrangements which includes notification to An Garda Síochána should any future concerns be identified.