A senior hospital doctor has been cleared of intentionally hastening the deaths of two terminally ill babies by administering a large dose of a paralysing drug.

Consultant neonatologist Michael Munro, 41, injected the two children, known only as babies X and Y, with muscle relaxant pancuronium after they suffered violent body spasms in the moments before their deaths, in an act alleged to have been "tantamount to euthanasia".

But in a landmark case for the medical profession, the General Medical Council yesterday said it accepted the doctor's belief that the babies were in distress and his intention had been to "relieve suffering" rather than to hasten death.

Dr Munro, however, still faces disciplinary action after the GMC ruled he had fallen below the standard expected of a registered medical practitioner by misleading the investigation into the babies' deaths by failing to tell a colleague he had prescribed pancuronium previously. He was cleared, however, of misleading the inquiry with dishonest intent.

Dr Munro, of Aberdeen, gave no reaction as the panel chairwoman read out the findings and did not comment on the ruling. His wife also declined to comment at their home last night. The doctor denies his fitness to practice is impaired by reason of misconduct.

The GMC is expected to announce its decision today.

Dr Libby Wilson, a spokeswoman for Friends at the End (Fate) in Scotland, welcomed the ruling concerning the babies' deaths. She said: "It was totally ridiculous. It was patently obvious he was relieving the symptoms which were causing illness and suffering of the babies and parents."

However, Dr Peter Saunders, of the Care Not Killing Alliance, said: "By giving 23 times the usual therapeutic dose, the doctor involved clearly intended to end the life of the neonate under his care by paralysing its respiratory muscles so that it could no longer breathe.

"Although the GMC has recognised he would have been motivated by a desire to ease his patient's suffering, this desperate act was both unethical and unnecessary.

"It is simply not necessary to kill the patient in order to kill the pain. This case underlines the need for neonatologists to obtain proper training in palliative care, as emphasised by the recent Nuffield Report."

A spokesman for the British Medical Association in Scotland said: "The duty of a doctor is to ease suffering and to provide treatment and care for patients so that is obviously within the bounds of the law. Physician assisted suicide is illegal and the BMA does not support that but it is different when the doctor alleviates suffering."

The hearing was told that baby Y was born on June 20, 2005, two weeks premature, and baby X was born on December 5, the same year, more than three months early.

Dr Munro was working at the city's maternity hospital in 2005 when both babies were admitted.

After speaking to both parents and with their explicit consent, he administered 2000mg of paralysing agent pancuronium allowing them to die peacefully.

Both children had suffered complications during pregnancy, with baby X suffering a serious brain haemorrhage and baby Y born with pulmonary hypoplasia and pulmonary hypertension.

Dr Munro admitted the drug had hastened their deaths by stopping their breathing.

In its ruling, the panel said: "In the particular circumstances of the cases of baby Y and baby X, the panel is not satisfied so as to be sure that your conduct was inappropriate.

"In reaching that conclusion, the panel accepts: your evidence that you believed the babies were in distress that had not been and could not be relieved by morphine; that there was a lack of clear, specific professional guidance; and that it is undisputed that your intention was to relieve suffering rather than to hasten death.

"Though Professor Marlow gave evidence that, in his opinion, it was unlikely these particular babies were in fact suffering distress, he was unable to exclude that possibility."

The hearing resumes today.