Primary school teacher Rita Van Gordon is going through the sort of anguish any mother does when she loses a child.
Her eyes brim with tears as she remembers what a lovely boy her eldest son, William, was. She finds it painful to talk about the potential his life held: four A-levels, a university degree, the £50,000-a-year job he secured at just 23.
What makes Rita, 51, different from other grieving mothers, however, is that her son is not dead.
William, now 28, has simply cut her out of his life - in the most extraordinary of circumstances.
Three years ago, then happily engaged, William was befriended by a man who described himself as a Buddhist monk.
From the start, Edo Shonnin exerted a remarkable influence on the young retail manager, encouraging him to convert to Buddhism and convincing him to think again about every aspect of his life.
Unfortunately, somewhere in this 're-thinking', William changed - and Rita's life fell apart.
First her son quit his job, then he split up with the woman he had wanted to marry. He shaved his head and donned the robes of a Buddhist monk.
But it wasn't the external changes that worried his family; it was the ones that seemed to alter his very personality.
He became distant - "odd", says his mother - and often fell into weird trances. He started speaking in a strange accent, a cross between Dutch and South African, even though he was Cheshire born and bred.
Less than two years after he met Edo, he pretty much severed all ties with his parents. The last time they saw him was across a courtroom in April 2007, as he wanted to sell the property he jointly owned with his father.
Today, William lives with Edo in the Welsh countryside, where the pair have set up a Buddhist retreat.
But his mother believes he has been coerced into this life - trapped in some brainwashing cult by a man who is, at best, someone who likes to reinvent his own life; at worst, a dangerous conman with a talent for deception.
The police have been involved in the increasingly acrimonious tug of war between William's parents and his Buddhist guru - with accusations being hurled on both sides.
Rita and her husband Bill, an engineering consultant, hired a private detective to investigate Edo and discovered he is a twice-married Glaswegian, rather than a holy guru. And they have tracked down people they claim are former "victims" of his methods.
Last year, in desperation, Rita even attempted to have her own son sectioned under the Mental Health Act, claiming brainwashing meant he didn't know his own mind.
"The truth is I cannot simply walk away and leave William to be destroyed by this man," she says with a heavy heart.
"We know he is a charlatan and my son has been taken in.
"If I could talk to William, I believe I could get him back. But we are never allowed to be alone with him.
"We have seen our son change from a bright, enthusiastic, confident young man, devoted to his family, to a hostile, closed-down, brainwashed zombie.
"Whenever I phone William on his mobile, Edo answers and says: 'He's busy.' We are not allowed to visit.
"Occasionally I get through to William, but he often says: 'How did you get this number? Don't call here again.'
"It's just unbelievable, but we've consulted a cult expert and much of it is a recognised form of brainwashing."
In October 2005 - already despairing at the path her son was on, but unable to get through to him in person - Rita wrote to William.
"It was a difficult but I hoped it would bring him some comfort," she says.
"I wrote: 'Always remember I am your mum, and that my love for you is unlimited and unconditional. The bond between us is unbreakable. Nothing is more important to me than your interests and well-being, and nobody will ever put you first as I do. Don't let yourself be persuaded otherwise.'"
It is a recognised fact that even the brightest, most strong-minded individuals can fall victim to dangerous cults. It's this thought that Rita Van Gordon holds on to.
The alternative - that her son simply doesn't want to know his own family - is simply too terrible to contemplate.
The speed and intensity with which William seemed to change certainly supports her theory.
One of four children, William was by all accounts a bright child. "He always tried very hard at whatever he did," his mother recalls.
"He was captain of the school football team. He swam for the local swimming team. He was a soloist in the choir. Academically, he was great. He got four A-levels and a place at Durham University. We were thrilled for him, and so proud."
William's choice of subject at university - geo-science - seemed to sum up his practical nature. It was there he met his future fiancee Helen, and seemed set on a high-flying life.
After graduating, he got a job with a retail group and was soon commanding a £50,000 salary and company car.
Yet he wasn't happy - even his mother knew that. The corporate life left him dissatisfied and he started applying for jobs in the charity sector to "do something worthy".
But after several rejections, he decided to go on a Buddhist retreat to France. His parents were more bemused than worried.
"He was going to this place called Plum Village to think about his life. We didn't think it that unusual as he was always a curious young man who had an appetite to try new things."
In fact, William asked his mother if she would like to go with him. She regrets her answer: that she was unable to take time off work.
"I wonder now if he was just ripe for the picking," she says. "He was brought up Catholic. We weren't an overly religious family, but he was spiritually curious and I think he was looking for something when he met Edo."
At first his family was happy that William had 'found himself' on the trip. He returned buzzing with excitement about his new friend - a Buddhist monk who was 'inspirational'.
Soon Edo came to stay with William in the house he'd bought with Helen in Manchester. He was welcomed.
"We all felt sorry for Edo because he told us he had cancer," remembers Rita. "He'd had a terrible life. He said, too, that he'd lost his parents, wife and children in a car accident.
"At first he seemed everything you'd expect from a Buddhist monk. He wore long brown robes and constantly stroked beads around his neck."
In time, though, alarm bells started jangling. First there was the food: although he claimed to be a strict vegetarian, Edo tucked into roast dinners during his visit to Manchester.
"He said that he would politely accept whatever food was put in front of him," says Rita.
"But he smoked quite heavily, too, and was very fond of gin, wine and Guinness. This struck me as odd for someone so supposedly spiritual.
"Odder still was that he managed to eat with such gusto when he supposedly had throat cancer.
"Another weird thing was his accent. He spoke with this odd foreign accent, even though he is Scottish. I guess it made him more authentic."
Edo was supposed to stay with William and Helen for a week. After a month passed, Helen became concerned.
William's reaction wasn't to ask his friend to leave - but to buy him a caravan to live in. "He got this caravan for a few hundred pounds, but it wasn't good enough for Edo, so the next thing we knew William was paying for a bedsit for him," Rita recalls.
"We were a bit worried, but William is very generous, so we didn't make a big deal about it.
"He kept talking about what an amazingly good person Edo was, how money didn't matter to him, how sound his values were. He claimed he had become 'enlightened' by him, but when I asked what he meant, he couldn't tell me.
"Once, he even said Edo could make himself disappear. He was already under Edo's spell."
Once Rita started questioning aspects of Edo's life story, the whole thing seemed to unravel. "He claimed to be a surgeon and a psychiatrist, and to have worked extensively in war-torn countries for Medicines sans Frontieres, but when I asked him about his time in Iran - where I have been twice - he clearly had never been there.
"He said he had studied at Yale and Cambridge, and had written 32 books. But it didn't stand up to the mildest scrutiny - he couldn't tell us what the books were or what college he was at at Cambridge."
Suspicions aroused, Rita turned detective. She contacted monks at the French retreat who told her Edo was not a monk, but had been so keen, as a layman, that they allowed him to wear robes and to do "guided meditations".
Rita is furious that they gave him such responsibility when he was clearly ill-qualified.
William, though, would not hear a word against his friend. "By then we were convinced Edo was just after William's money, and told him so," Rita says.
"He wouldn't hear of it. Every time we tried to talk to him, he would just sit down and leave us, or go into some sort of weird trance. It was scary.
"By this time, he had lost loads of weight - about two stone - and he was always too busy to sleep.
"Bill and I started to look on cult awareness websites, and were horrified to find out that food and sleep deprivation are known tactics for recruitment into cults.
"It weakens them and makes them more susceptible to brainwashing. With every day that passed came more evidence that something sinister was going on.
"William started saying things like, 'I'm so enlightened that even the flowers smile at me,'" Rita recalls.
"We wondered if he was on drugs, but I think it's more likely that he was just hypnotised by this man."
At the end of 2005, William and Helen split up. "Helen had a breakdown. She was devastated. She couldn't convince him that Edo was anything other than genuine," Rita says.
"The next thing we knew, Edo had moved in with William. From there, it all went downhill."
As well as buying a home with Helen, William had invested in a 'buy to let' property with his father. One day, William announced that he wanted to sell up, to put money into a business venture with Edo.
Bill refused - and the ensuing legal wrangle ended up in court. It ruined what was left of their relationship.
Rita recalls: "The court asked if William had 'capacity issues' - in other words, 'Is he all there?'
"I said: 'No, he has been brainwashed.' I even tried to get him sectioned under the Mental Health Act, but our GP said William would have to agree to be examined, which he wouldn't."
It was at this time that Rita employed a private detective to find out more about Edo's past. She discovered that his real name is Edward Penny and that he has been twice married to British women.
"One of his ex-wives said that Penny was evil and that the mere mention of his name made her shudder with fear," Rita says.
"We also spoke to his sister, Suzanne Richardson, who hadn't seen Edo for more than 20 years. She said her mother was still alive - so the car crash he talked about was clearly a lie."
The situation became murkier. As their son became more deeply involved, whispered doubts turned into full-blown confrontations.
At one point Edo went to the police, claiming that Bill had attacked him - something he vehemently denies, and no charges were ever brought.
He then claimed Bill was keeping radioactive material at home - again prompting a police visit.
"It was rubbish, of course, but it shows what sort of a man we are dealing with," says Rita. "He will do anything to turn our son against us."
In March 2006, William and Edo moved to Wales, setting up the Pine Forest Sangha retreat in a rambling property William bought, using his savings and a mortgage, for £300,000.
Two months before they moved in, his mother tried again to get through to her son. "We went out for lunch. Edo insisted on coming too.
"As the day wore on, I felt William was becoming more like his old self - more chatty, less weird and distracted - but Edo was visibly furious.
"Just as I started to talk to William about his future," Rita recalls, "Edo became 'ill' and asked William to go to the loo with him. When they came back, he was different: blank - like a robot.
"He used to have such a wicked sense of humour but now he is so serious. He looks so unhappy. He has just cut himself off.
"None of his siblings or friends can get through to him either. My daughter missed him terribly at her wedding this year. She broke down at the altar because of it."
Rita recently made contact with a former guest at her son's retreat. What was said left her devastated. "This woman described William - my clever son - as being lovely, but a bit simple - like someone with learning difficulties.
"She said he shuffled rather than walked, and that she thought there was something seriously wrong with him.
"I worry that Edo keeps him so exhausted with tasks that he can't even think for himself."
The Mail has learned that this former guest has herself launched a complaint to the Charities Commission about the retreat.
Rita is also concerned that Edo claims he has been visiting schools and colleges across Wales to spread his message. "It beggars belief. We have seen our intelligent young son suspend all reasoning and end up a brainwashed zombie.
"Surely he can't be given the chance to wreck other young lives too?"
But even if Edo's reputation is challenged, there is no guarantee that William will "comes to his senses", as she puts it.
Rita clings to the hope that when she does get see her son again, she will be able to get through to him.
"The last time I saw William, before the court case, he tried to hypnotise me. He kept saying: 'Look into my eyes.' I snapped back - as I used to do when he was three, and being naughty: 'Just stop that, William.' And he did.
"That gives me hope. He is still my boy. I can still get through to him on some level. Now I just have to get through on a deeper level, and stop him throwing his life away."
