In the summer of 2012, George Wilkins, a documentary filmmaker, was in his friend's health food shop when a customer walked in, looking exceptionally ill.
"He walked up to the counter and asked for hemp oil to help treat his lung cancer," explains the 29-year-old from Hull.
"When I quizzed him, it turned out he was muddling hemp oil with cannabis oil. Still, I thought, why would he want that? So when I got home, I started researching it and found some quite compelling scientific evidence about the huge benefits of cannabis oil for cancer patients. Meanwhile, the health of the guy who came into the shop improved significantly within just a month of taking it."
Wilkins, who runs a film production company, wasted no time in spotting an opportunity to make a documentary and, two-and-a-half years on, Project Storm has just launched on YouTube. Crowd-funded by supporters and following the stories of six UK cancer patients (two of whom are children) who are being treated using cannabis oil, the film is controversial, but is seen as big news by a fast-growing community that wants to promote this more integrated approach to oncology.
Cannabis oil, which requires an extra stage of preparation once the plant has been harvested, is basically made up of cannabinoids such as CBD and the psychoactive THC, the active chemicals found in the plant that cause the "high" sought by recreational users.
Already forming the basic make-up of the pharmaceutical cannabis-based drug Sativex, which is used to treat MS, growing scientific research now suggests that cannabis oil may also possess anti-cancer properties that help stem the growth of malignant tumours. The crème-de-la-creme is seen as 1:1 oils, which contain equal amounts of THC and CBD, which, when combined, are more effective. CBD also has the added benefit of moderating the psychoactive effects of THC.
"I'm not claiming cannabis oil is a miracle," says Wilkins, who explains that the six patients that the documentary follows range from three to 75 years old and are being treated for various cancers including prostate, glioma (brain), bowel and GBM, a common childhood cancer. "Nor am I suggesting people should stop more conventional treatments for cancer. In fact, my whole aim with the film is to blow the hyperbole out of the water. After all, if you couple the fact that there are very polarised opinions on this issue with the fact that those who shout the loudest get their views heard on the internet, it means that cancer patients looking to make a genuinely informed choice can find it impossible. I wanted to try and fill that gap."
It is true that the film points out some of the limits of current research, as well as highlighting some of the potentially negative aspects of cannabis oil (side effects such as anxiety, for example, as well as the problems of scammers selling olive oil as cannabis oil).
Moreover, the film does not hide the fact that the outcomes for the six patients are not all positive. But it would be a stretch to call the film objective, with Wilkins himself responding to the question, "Did you contact organisations such as Cancer Research UK?" with the answer, "Why would I want to do that?" Cancer Research UK, he explains, claims there isn't enough reliable evidence to prove whether cannabinoids can effectively treat cancer, whereas he'd like to see the drug legalised. Moreover, Wilkins chose YouTube over channels including the BBC "because the channels wanted to change the slant I took".
There was a second reason, he adds. "They didn't want me to focus so heavily on Jeff Ditchfield because of his past convictions. But Jeff is the pivotal person in the whole movement."
Indeed, having founded the organisation Bud Buddies in 2002 – which supplied cannabis to ill and disabled people free of charge – and now a regular lecturer on the medical properties of cannabis to the Royal College of GPs, Ditchfield is recognised as a hugely influential figure in the development of medicinal cannabis in Britain.
For five years, Ditchfield operated from a cannabis coffee shop in Rhyl, north Wales that, despite being under constant surveillance and subjected to six police raids, became a key part of the local community.
But in 2007, he resettled in Spain, where Bud Buddies now receives support and sponsorship from companies within the cannabis industry, as well as raising funding from books and seed sales. "I chose Spain because unlike in the UK, supplying cannabis in Spain is only illegal if you profit in some way," says Ditchfield, who put Wilkins in touch with the six subjects of the documentary. "Spain has a far more open-minded attitude to research in medical cannabis."
Wilkins' endeavour cannot have been made easy by the fact that even some experts who have made headway with research refused to get involved in the film. Dr Wai Liu at St George's University in London, whose research suggests that cannabinoids possess anti-cancer properties that help to stem the growth of malignant tumours, told The Independent that he was among them.
"There is lots of evidence to suggest that cannabis might work with cancer patients, but as it stands there is still no firm proof on humans," he says. "I didn't want to be associated with a film where I couldn't be certain that this picture would be presented impartially."
Dr Emma Smith, a senior science information officer at Cancer Research UK, shares his concern. "I haven't actually seen the film, but following six patients in this way is purely anecdotal and those who survived might have done anyway without taking cannabis oil.
I am also worried that the potential benefits of cannabis in cancer treatment are often presented in a misleading and overhyped way. Furthermore, cannabis is both illegal and could interfere with other treatments you are having. Finally, most of the research that has been done to date is on cancer cells grown in the lab or on mice."
This is not to say that cannabis has no future role, she says. "But as it stands, we still need proper trials to know for sure whether it has any effect and if so, for what types of cancer, at what dose and in conjunction with what other treatments."
These trials can't come soon enough, believes Peter McCormick, a lecturer in Cell Biology at the School of Pharmacy at the University of East Anglia, who earlier this year found that THC could help combat the growth of cancerous cells. "There are hundreds of reports out there and I do get concerned about them being written off as some anomaly or people trying to push recreational drugs into a legalised setting. The reality is that there are plenty of cases where cannabinoids do seem to be doing something and our study is further evidence that more research needs to be done."
As for Wilkins, he hopes that, at the very minimum, the film provides cancer patients with a fuller picture than they've had access to so far and that it acts as a catalyst in what everyone agrees is a much needed debate.