"Audit Scotland found a small number of instances where unavailability codes were used inappropriately, " the watchdog stated.

BBC: Audit Scotland warns NHS waiting list information 'poor'

Ms Lamont was referring to a report by Audit Scotland which tracked relatively extensive past use of "social unavailability" codes to exclude patients from waiting time guarantees.

BBC: First minister's questions: Health of a national treasure

The Scottish Parliament's public audit committee suggested samples of patient records were tested to make sure the use of social unavailability codes on the NHS computer system was "appropriate".

BBC: MSPs call for more accurate NHS waiting time logs