Patient medical records from a Co Mayo hospital have been found in a bin at a housing estate in Ballina.
The handwritten notes, relating to a number of patients of St. Joseph's District Hospital in Ballina, were discovered by a litter warden.
The HSE West has confirmed to MidWest Radio that the notes were "discarded inappropriately" and returned by the warden.
An investigation is underway, and HSE West has written to all of those involved and apologised to patients and their families.
The HSE statement states the files were staff notes only, and insists there was no unauthorised access to any permanent records of patients.
The statement says the matter has been brought to the attention of the data commissioner.
Councillor Michael Kilcoyne, who was also contacted by a number of patients and families, has hit out at the HSE.
"I want to put on record, and I expect to get the support of all public representatives," Mr Kilcoyne said.
"I want the Minister for Health to initiate a public inquiry into this matter, and I want whoever's responsible to be dealt with and taken out of the picture."