Jehovah's Witness parents in Queensland have come under fire for denying their terminally ill son a life-saving procedure.

Their seven-year-old boy has severe liver disease and doctors have said he will die without a transplant.

However, his religiously devout parents are refusing to consent to a blood transfusion - an essential part of the liver transplant procedure.

In an attempt to save the young boy's life, Brisbane's Lady Cilento Children's Hospital has launched a Supreme Court challenge to allow medical staff to administer the necessary blood transfusions during the operation.

Documents lodged as part of the court challenge state that the parents are aware their son will die within two years without the treatment.

Brisbane's Lady Cilento Children's Hospital has launched legal action to allow them to perform a lifesaving blood transfusion, as part of a liver transplant, on a seven-year-old Jehovah's Witness

Many of the doctors involved in the boy's treatment were unable to comment, as the matter is currently before the court.

But prominent Australian medical practitioner Dr Ross Walker believes religion has to stand aside when a child's life is at risk.

"It's my opinion religion should have no role in the operating theatre," Dr Walker said.

"We're talking about life and death situations, as opposed to someone's personal philosophy - especially when you're inflicting that personal philosophy on your child."

The boy's doctors are hoping for a positive and speedy outcome in the legal challenge.

The sicker the boy gets, the harder it will become to carry out the liver transplant at all.

In a court affidavit, one of the boy's doctors has given him a good chance of survival if the liver transplant and blood transfusion occur soon.

Dr Tom Aechtner, a lecturer in the history of religious thought at the University of Queensland, believe these parents possibly aren't looking at this as a case of life and death - but a case of god's will.

"For Jehovah’s Witnesses, essentially there are no exceptions for the acceptance of blood transfusions," Dr Aechtner said.

"Not accepting blood transfusions, perhaps even in a situation where it might be a case of life and death, is essentially considered a small price to pay for eternal life," he said.

There are many controversial cases relating to the children of Jehovah’s Witnesses and blood transfusions.

In Sydney this year, a pregnant Jehovah’s Witness and her baby died after the woman refused a blood transfusion .

Also in New South Wales, the Supreme Court overruled the wishes of a 17-year-old Jehovah’s Witness suffering from a lethal form of blood cancer in 2013.

The doctors were able to forcibly provide treatment to the boy until his eighteenth birthday – when he was given the option to refuse further treatment.