A Co Armagh care home cannot take new admissions after an unregistered nurse was left in charge of the facility.
Northern Ireland's health watchdog uncovered a number of serious failings at St Francis Private Care Home in Portadown during an unannounced inspection last month.
The Regulation and Quality Improvement Authority (RQIA) raised concerns about the health and welfare of residents, as well as the possibility that patient confidentiality had been breached.
The regulator also said it was "not satisfied that there were robust systems in place to prevent patients being placed at risk of harm or abuse".
The RQIA was so concerned by the conditions in the home that it made a referral to the adult safeguarding team at the Southern Trust.
A spokesman from the home denied that any residents were ever put at risk and said it had appealed the RQIA decision, as no consideration has been given to the "years of loving care to our residents" and the actions taken to protect residents during the pandemic.
The RQIA carried out an unannounced inspection of the home on September 8 and found that "a pre-registered nurse, who was not on the Nursing and Midwifery Council register, was taking charge of the home in the absence of the registered manager".
The inspection report continued: "RQIA evidenced that, on the occasions when the pre-registration nurse was on the duty rota and taking charge, staffing arrangements were not adequate to ensure the health and welfare of patients in the home.
"RQIA did not receive a satisfactory explanation as to why this nurse had been allowed to work unsupervised, nor was there any understanding as to how this placed patients at risk of harm."
It is not the first time RQIA inspectors have identified issues relating to the recruitment of staff at the home. In October last year management was summoned to a serious concerns meeting after an inspector found proper checks were not being carried out on newly recruited staff.
A statement from the home said the member of staff relating to last month's inspection had not been honest in either their application form or during interview.
"We had no reason to believe that a practitioner with vast years of experience would give false and misleading information both on the application form and interview," it said.
It added that the home has put in place "stringent recruitment measures" and he is "categorically certain that will in future prevent any occurrence of this nature".
It continued: "From now on, no member of staff will be permitted in the building until all checks are completed. It is also our utmost conviction that the current restrictions on the admissions will prevent vulnerable residents from being placed in a home which has continuously over the years given proof of prime care and attention 24 hours a day.
"The recent and most unfortunate incident, as the individual had no contact with any residents, was not typical of the standards of care provided by us over the years and it is much regretted... at no time ever, was any of our residents put at risk."