DOCTORS have made an urgent plea to the Supreme Court to help them save a Jehovah's Witness girl, 4, who is dying of leukaemia.

Justice Richard White yesterday heard that the girl, who cannot be identified, was this week diagnosed with cancer of the blood and bone marrow.

Doctors said she should have a blood transfusion but her parents objected on religious grounds.

The hospital turned to the court, arguing that without treatment the girl would die.

In emotional scenes yesterday, the girl's father wept as he spoke of his love for his daughter, but said their faith prohibited blood transfusions.

"We adhere to strict Bible principals and one of those is to abstain from blood.

"We want the best possible treatment for (her) and the hospital are doing a great job ... the only thing we don't consent to is the issue of blood," he said.

The hearing, in South Australia, came two years after the court made a legal-first ruling to save a boy, 10. Yesterday Justice White - who also heard the boy's case - said treatment was in the little girl's best interests.

Paediatric oncologist Dr Petra Ritchie said the treatment would give the girl a 90 per cent chance of survival.

Asked what would happen otherwise, Dr Ritchie replied: "She will die ... I would say in a matter of weeks."

Lawyer Ken Gluche said the parents, "deeply love their child ... they do seek the best medical care for (her), the only issue relates to the blood ... It's not like they are acting with callous disregard for her wellbeing or her future".

He said their Jehovah's Witness beliefs were not forced on them and "clearly it's their genuine beliefs".

Justice White handed down his decision immediately, ordering that the girl undergo a blood transfusion.

Originally published as Judge rules on blood for cancer girl