“My priest checked the Bible and said he couldn’t find any reason why we shouldn’t go ahead,” says Fvanhoorn. “My wife, Johanna, was reluctant at first, but she was in terrible pain and I wanted it to help her. We tried it and, within five minutes, her pain went. Within a month, my sight began to get better. It was incredible.”

They were results that thousands of other sufferers have reported experiencing with cannabis but there was one unwelcome side-effect; the old man’s son, also a devout Christian, fell out with him. The son wanted nothing to do with illegal drugs and refused to visit a home where the weed was being used.

So imagine Fvanhoorn’s delight, when, on September 4 last year, the Dutch government introduced a fully legal, licensed medicinal cannabis programme. He, and thousands others who suffered from chronic pain, multiple sclerosis, HIV and terminal cancer, could get a doctor’s prescription for pharmaceutical-grade cannabis approved by the Government. Sufferers could now buy the drug legally from chemists without the stigma of skulking around smoky streetside “coffee shops” where illegally produced grass is sold while the State turns a blind eye.

The Netherlands, held in high esteem for its collective liberal conscience and caring social values, had led the way again. It had introduced the world’s first legal medicinal cannabis programme at a time when countries such as the UK were dithering over pleas from sick people to let them take the drug legally. It seemed the perfect solution to a prickly problem. For many, it was a dream come true.

But 11 months on, the dream has turned into a bit of a nightmare. Remarkably, the State has managed to produce the world’s only narcotics operation to run at a loss. Stockpiles of unused state “mediweed” have doubled. The two producers licensed to grow cannabis are threatening to sue the Government, while patients are turning away from legal cannabis and returning to the coffee shops and a patients’ charity. The programme, you might say, is going up in smoke.

According to Fvanhoorn, and thousands like him, there are two problems with the state mediweed: “It’s too expensive and it doesn’t work. I dropped it straight away. Now I get it from a charity which, technically, is illegal. But at least I don’t have to watch my wife suffer.”

To see how we got here, we must go back to 1972. That was when Mellow Yellow, the first coffee shop to sell cannabis openly, was established. It was controversial at the time, but hundreds more soon followed (there are thought to be 1,600 today) while politicians adopted a policy of informed tolerance. It is still technically illegal to possess unprescribed cannabis in the Netherlands, as it is to grow or traffic it.

In the 1980s and 1990s, when anecdotal evidence began to emerge that smoking marijuana alleviated pain and reduced muscle spasms in multiple sclerosis sufferers, the founder of Mellow Yellow, Wernard Bruining, began canvassing his fellow coffee shop owners about the possibility of helping out real medical cases. In 1994 they founded a “mediwiet” (mediweed) programme, selling cannabis at a discount of up to 50 per cent to sufferers who provided a letter from their doctor. Patients were delighted but the Government was uneasy. Coffee shops acting as de facto pharmacists meant well, but could not guarantee the price or quality of the drugs they were selling. It was time, the politicians agreed, to introduce regulation.

In 2000 the Office of Medicinal Cannabis, part of the Dutch Ministry of Health, Welfare and Sport, was set up. After three years of trials the current system was introduced, with two proven and respectable Dutch growers, the Stichting Institute of Medicinal Marijuana (SIMM) and Bedrocan, being given five-year contracts by the government to produce up to 500kg and 200kg of cannabis a year respectively. To make the scheme legal, the Dutch government had to abide by a UN convention requiring it to set itself up as a monopoly grower and supplier of the drug. For James Burton, SIMM’s director, this meant that his dream of providing legal cannabis to sick people could become a financially viable reality. For years, Burton, 56, an American Vietnam veteran, had been growing and supplying medicinal cannabis to Dutch doctors, hospitals and individual sufferers with the tacit understanding of the Rotterdam police. A genetic disorder in males in his family had resulted in his father and two brothers going blind with glaucoma; he believed smoking marijuana had saved his sight, and wanted others to benefit. Now he had his chance — or so he thought.

“Hell, if you are one of two people licensed to produce something for a monopoly, you’re pretty financially secure, right? Wrong,” he says. Burton, a passionate advocate of medicinal cannabis, became a cause célèbre in the US in 1987, when he was jailed for a year for growing the drug to save his sight. When I meet him he is standing chest-deep among his cannabis plants at a secret growing facility. The air is thick with the pungent smell of marijuana, but there is something else in the atmosphere: anger.

“The Government has screwed things up to the extent that I’m losing €10,000 (£6,800) a month,” he says.“ I’ve had to warn patients that my product doesn’t work but the Government won’t let me produce anything better. I plan to sue the Office of Medicinal Cannabis for wrecking my business and, unless things change drastically, I plan to pull out of it all in December.”

So what went wrong? Burton agrees with Fvanhoorn: price and quality. The latter — at least for medicinal users — is determined by levels of cannabinoids in the plants. These are compounds that react with receptors in the brain that control pain and mood. Varieties of cannabis have more than 60 different cannabinoids, but the two that seem to help MS, cancer and glaucoma sufferers most are tetrahydrocannabinol (THC) and cannabidiol (CBD).