A consultant neurologist has admitted allowing an "inaccurate" and "illogical" cause of death to be recorded on a child's death certificate.
Dr John Hanrahan was involved in the care of 17-month-old Lucy Crawford.
She died at the Royal Belfast Hospital for Sick Children in April 2000.
He faces a series of allegations relating to his conduct after her death, including failing to tell the coroner's office of any concerns regarding the fluids Lucy received while in hospital and allowing an inaccurate cause of death to appear on her death certificate.
Lucy, one of five children whose deaths were examined by the Hyponatraemia Inquiry, was originally admitted to the Erne Hospital in Enniskillen with a history of drowsiness and vomiting.
Her condition deteriorated significantly the following day and she was transferred to Belfast in a "moribund state", where Dr Hanrahan became involved in her care.
A death certificate, issued on May 4, 2000, stated Lucy died as a result of cerebral oedema, due to dehydration, due to gastroenteritis. However, a subsequent inquest in February 2004 found she died from cerebral oedema, due to dilutional hyponatraemia, due to excess dilute fluid and gastroenteritis.
At the time the coroner said errors in the amount of fluids Lucy was given led to the hyponatraemia which ultimately resulted in her death.
During the first day of a fitness to practise hearing by the Medical Practitioners Tribunal Service in Manchester yesterday, two allegations facing Dr Hanrahan were admitted and found proved.
They were that he "permitted the cause of Patient A's death to appear on the death certificate as cerebral oedema due to dehydration" when it was "inaccurate" and "illogical".
The case, which will establish if Dr Hanrahan's fitness to practise is impaired, is scheduled to last nine days and follows the damning Hyponatraemia Inquiry report in January 2018.
In his findings, inquiry chair Mr Justice O'Hara said: "I am satisfied that Dr Hanrahan knowingly permitted an inaccurate description of the cause of death to appear on the death certificate."
He added it was a "matter for gravest concern and cannot be excused by what I accept was his genuine sympathy for the family or a desire to help them expedite the funeral arrangements".