Adam Koessler was charged at a Brisbane hospital last Friday for supply dangerous drugs to a minor after giving his two-year-old daughter, Rumer, medical grade cannabis oil in a desperate bid to treat her stage 4 neuroblastoma cancer.

Mr Koessler said he had travelled from Cairns to Brisbane for his daughter's treatment and had been at a meeting with her oncologist at a Brisbane hospital on January 2 when he was arrested and charged.

He said he was charged with supplying dangerous drugs to a person under 16 and possessing dangerous drugs and was bailed to appear at Brisbane Magistrate's Court on January 20.

He said his daughter had taken cannabis oil, mixed with coconut, as an infusion in her food and the results had been remarkable.

Asked if he had a message to the public he said that after his daughter was diagnosed he wanted to do everything possible to maximise her chances of living, which had been put at 50/50.

"I saw first hand that the cannabis oil was extremely beneficial and I hope I simply did what any father would do."

Mr Koessler has been bailed to face court on January 20 but as part of his bail conditions is unable to have contact with his daughter.

Since being forced off the cannabis oil last week, Rumer’s condition has dramatically worsened and she is now in intensive care on morphine.

The arrest has outraged medical cannabis advocates, who claim parents should have the right to treat their own children with an effective medicine.

Newcastle-based NSW Hemp Party spokesman B.J. Futter said politicians and bureaucrats were out of touch with the way that medical cannabis was operating in the community.

 "To separate states into red tape mine fields and to keep this medicine from the population is an atrocity when one actually sees the extent of those who are ill," Mr Futter said.

Referring to the way the child was put on to opiate pain killers after her father's arrest, he said "the current legal position regarding the enforced medical treatment of an innocent child is unconscionable".

Mr Koessler said the oil, which contains none of the compound which gets recreational users high, was having a “miraculous” effect on his daughter.

“What we saw when Rumer was given the medical cannabis oil was nothing short of miraculous,” he said. 

“Her cancer-ridden little body was alive again – Rumer had almost instant quality of life.

“She would say ‘Daddy, tummy’s not sore’ and she would be able to eat like a champion and began to gain weight.

“Her energy was up and she wanted to go outside with me instead of lay on her back with her legs curled up. 

“Her skin colour came back, her eyes were sparkling again and we just looked at each other in complete amazement.”

Mr Koessler’s arrest comes as the NSW government rushes towards medical marijuana reform, with a range of clinical trials announced last month.

Tamworth mum and medical marijuana crusader Lucy Haslam said Mr Koessler’s arrest had the potential to set back the national debate.

“Queensland Premier Campbell Newman knows about this issue and I find the timing very interesting,” Mrs Haslam said.

“This has the potential to be a real election issue.”