Complaints about NHS care cannot always be investigated properly because of medical records going missing, the public services watchdog has said.
Ombudsman Nick Bennett said many people were left "suspicious" and thought there was a "darker motivation".
One woman whose notes went missing said she no longer trusted what doctors said and had lost faith in NHS transparency.
The Welsh NHS Confederation said staff were "committed to the highest standards of care".
In a report called Justice Mislaid: Lost Records and Lost Opportunities, Mr Bennett found 70% of 17 cases he looked at in Welsh NHS hospitals and care settings could not be properly investigated because of lost documents.
Source: BBC News, 10 March