Gardaí have confirmed that they are investigating the sudden death in late 2012 of Francis Loughney, who became ill while being cared for as a long-term resident of Áras Attracta in Swinford in Co Mayo.
It's understood the local coroner asked the gardaí to investigate.
It's also understood that the HSE has conducted its own internal investigation into Mr Loughney's care which attempts to discover why he did not see a doctor during his final five days of life in the home, despite running a very high temperature and being given prescribed antibiotics.
HIQA has found major non-compliance with its care standards in the residential care centre for adults with intellectual disabilities in Co Mayo.
The treatment of residents during one meal at the HSE-run centre was described as "distressing" during an inspection last February.
Áras Attracta was accommodating 97 residents with intellectual disabilities when information from whistleblowers led HIQA to carry out an unannounced inspection last February.
There is an apparent conflict between what HIQA and the HSE say concerning what triggered the inspections.
In a statement the HSE said the inspections were undertaken "as a result of a notification of the death of a resident".
The health and social services watchdog's two-day inspection focused on nutrition and the use of restrictive procedures.
The report, published today, states that inspectors were concerned that practice in both areas required significant improvement to ensure the health and well being of residents.
On nutrition, some residents weights were under the recommended measurement and although the dietician had prescribed supplements and high calorie diets, there was no evidence in their daily record sheets that they were receiving these.
The report says mealtimes were not a pleasant experience nor a social occasion.
Inspectors observed some residents being offered spoonfuls of food in quick succession by some staff before the residents had swallowed and enjoyed the previous spoonful.
And some residents were not offered any drink for the duration of the meal.
There was also concern that residents went for 15 hours without food to facilitate staff duty arrangements.
Some staff were heard describing residents inappropriately.
After the inspection the HSE replaced the person in charge and HIQA's second inspection of the centre in May showed significant improvements although more have been recommended.
The HSE said since the two HIQA inspections 52 of 59 recommendations have been fully implemented and the remaining seven are under way.
The executive said governance within the service has been strengthened and the service being provided now is safe.
It said: "Residents and their families can be assured that all actions required by HIQA have been implemented and that management and staff will continue to work with residents and their families to provide the highest standards of care in the unit."
The HSE said the families of the centre's 99 residents were contacted to advise them of February's inspection and of the improvements that were under way.
It added that the families were again written to earlier this week offering a contact point and advising them of today's publication of the HIQA report.