A Dutch court ruled Friday that a 12-year-old boy suffering from a brain tumour had the right to refuse chemotherapy, rejecting his father's plea to order him to have the treatment.

Known only as David, the boy was diagnosed with the tumour in November which was operated on and removed. He was given radiation treatment and declared "clear," the court said in a statement.

Doctors then recommended he should also have chemotherapy "but David did not want any follow-up treatment... and was supported in this by his mother."

Dutch media reported that the boy, whose parents are divorced, wanted instead to try alternative medicine.

His father lodged a case with the court in northern Alkmaar against the local child services, arguing his son should be forced to have further treatment.

The boy has been assessed by child psychologists since he was going against medical advice.

They found that David was mentally competent and in good spirits with "a strong will to live," but was concerned the side-effects of the chemotherapy would affect his current quality of life.

While the judge said he understood the father's concerns, he "found there was no reason not to respect David's wishes," the court said.

"David can reasonably appreciate what he believes is in his best interests, and understands the consequences of his actions, including the negative ones," the court added.

"He has the right to self-determination, even if that is hard for the parents."

The judge also referred to Dutch law on euthanasia, which allows terminally-ill minors aged between 12 to 18 the right to opt to ask for help to end their lives.

The law clearly allows children of 12 and older "to make decisions about their treatment in life-threatening situations".

The father's lawyer told the Dutch news agency ANP they would study the ruling before deciding whether to appeal.