A doctor who gave a paralysing drug to two terminally ill babies, hastening their deaths, "felt in his heart" the children were suffering.
The doctor was involved in baby care at Aberdeen Maternity Hospital
Consultant neonatologist Michael Munro, 41, injected the two children at Aberdeen Maternity Hospital after they suffered violent body spasms.
A General Medical Council (GMC) panel heard he thought it was "horrendous to witness" for relatives of the children.
Dr Munro denied his conduct was below standard, dishonest or inappropriate.
The inquiry has heard the doctor's administration of drugs in 2005 hastened the deaths of two terminally ill babies and was "tantamount to euthanasia".
He gave 23 times the normal dose of a muscle relaxant, medical watchdogs were told.
When babies become weak with treatment withdrawal they can struggle to breathe, a condition known as agonal gasping.
Colleagues raised doubts about the treatment and an investigation was launched into the doctor's actions.
Asked on Monday how the parents of baby Y appeared, Dr Munro replied: "They were utterly distraught.
"If you put yourself in their shoes, they have already said their last goodbyes to their baby, then suddenly there are these massive, racking agonal gasps which appeared to build up - they were utterly, utterly distraught.
"The parents were in tears saying things like 'I can't take any more'. I took the decision then to administer Pancuronium."
He said he chose Pancuronium after reading a recent article in a medical journal.
The baby incidents both happened in Aberdeen in 2005
He said the drug appeared ethical and acceptable to be used in this situation and, following discussion with the family, told a nurse to fetch the muscle relaxant.
He said: "While [the nurse] was outside, I explained to the parents that this drug was to be used to ease the suffering but that one of the consequences of its use may be to hasten death.
"They were happy with that."
Questioned about why he failed to record the drug's use in the medical notes, Dr Munro denied he had attempted to hide his actions.
In the case of baby X, the doctor was again called to certify death and discovered the infant's faint heartbeat. Again the child began agonal gasping.
Dr Munro said: "I tried to explain that this was simply a reflex although I felt in my heart that this baby was distressed."
Following discussion with the child's family, Dr Munro made the decision to administer a dose of Pancuronium and the infant died a short while later.
He again denied his failure to record the use of the drug in notes was an attempt to hide his actions but conceded his note-taking had been inadequate.
Andrew Long, representing the GMC, underlined earlier that neither of the children's parents were unhappy with the doctor's treatment of their babies.