Unauthorised medical devices without a safety mark were implanted in children with spina bifida two years before the alarm was raised, it has emerged.
They were bought and implanted in three children during spinal surgery in Temple Street Hospital after bypassing a legal duty to tell a safety watchdog.
An investigation will get under way into how the devices came to be implanted.
The news comes as Health Minister Stephen Donnelly confirmed that doctors in Temple Street raised concerns about the use of the devices as far back as a year ago.
