Mr O'Rourke's story features in the Tamworth based documentary High as Mike, which has its local premier at the Capitol Theatre on Thursday night.

In December 2015 Mr O'Rourke got the startling news that his "flu that wouldn't go away" was actually terminal cancer, and that he needed to "get his affairs in order very quickly", that was, until he tried treating his cancer with medicinal cannabis, which at the time was still illegal.

"One month to live - I said f--k that, it's not happening," he said.

"My daughter Samantha did a lot of research and we decided to give it a go.

"I left the local cancer centre and checked in to Chris O'Brien House in Sydney for treatment."

Fortunately Samantha and her father also got in contact with Lucy Haslam, who together with her late son Dan, kick started an ultimately successful movement to legalise medicinal cannabis, although she has sadly had to continue fighting for fair access since.

"Lucy was kind enough to give me Dan's vaporiser - It was a privilege to use it," Mr O'Rourke said.

"The same person that helped Dan recommended I take pure THC (Tetrahydrocannabinol), and a lot of it."

Since being diagnosed Mr O'Rourke had lost over 50kg, and had a very poor quality of life.

"I was going backwards - I couldn't eat, I was constipated, I was dying," he said.

"As soon as I got on the oil my hunger came back, and I started eating an organic healthy diet.

"That was the main thing, being able to eat, but it also got rid of my asthma issues - using the vaporiser made my lungs stronger - I could run a half marathon now."

Mr O'Rourke also continues to receive immunotherapy, and targeted therapy, although has never had chemotherapy.

His 12 cm "black mass" has since shrunk to the size of his fingernail, and he also claims that several other ailments also dramatically improved, or even disappeared.

"The 'mother flower' is curing my cancer - some people don't believe that is possible, but I am a walking f---king billboard," he said.

"It is not just the cannabis, you have to eat and live a healthy lifestyle as well, but cannabis has allowed me to do that.

"I am only alive because of the 'mother flower', and because of my beautiful daughter."

Mr O'Rourke hopes that High as Mike doesn't just "win all the awards it deserves", but also changes perspectives of those standing in the way of medicinal cannabis access, and the stigma surrounding the issue in Australia.

"I was a recreational user most of my life - and that is part of the problem," he said.

"There are some people who want to get high, but there are a lot of people that need it medically, and we need to be able to see past that.

"It breaks my heart seeing the hardship that people are going through that can't get it, or are scared of accessing it because of laws and stigma.

"We are supposed to be the lucky country, but we have some ridiculous laws that are not helping anybody."