Joanne and Robert Hall dreamed of a better life in France, and of building a luxury golf resort in the Brittany countryside. But 10 years later her burned body was found encased in concrete and he was charged with murder. So what went wrong? Jon Ronson investigates

The Château de Fretay is a 100-acre estate in the Brittany countryside, with chapels and cottages and a lake and forests. From a distance, the place looks like a dream. Some teenagers from the village tell me that until a few weeks ago they'd go up to hang out with the children of the English couple who lived there. The mother, Joanne, always had an open fire and English breakfasts on the go. The place was so big and overgrown that one time they found a chapel in the grounds that nobody, not even the English kids, knew existed.

I park my car. There are hundreds of seedlings in little plastic cups in rows on tables, ready to plant but all dead now; abandoned plastic garden furniture is strewn everywhere, as if a tornado had come through; a statue of the Madonna and Child stands in some builders' rubble; and a swimming pool filled with rotten green water – two unopened bottles of Heineken sit there poolside.

I peer in through the window of the main house. It isn't, actually, a château. There's nothing castle-like about it. It's a big farmhouse. It is dark. The doors and windows are police-taped up, as they have been for the past seven weeks, since 4 September, so the place is a time-capsule of that weekend. There's a pack of playing cards on the living-room table, a beer on the arm of a comfy-looking leather chair, next to a folder filled with complicated-looking business plans. In the kitchen, the dishwasher is still turned on. You get the eerie sensation that Mr and Mrs Hall have just gone into another room and will probably return any second and have a bit of a fright to see a journalist peering in through their window.

The village mayor, Pierre Sourdain, a farmer, says he liked Robert and Joanne Hall very much. All the villagers say the same: they were impressive, charming, self-possessed. (Saying that, the people in the village speak no English and Robert Hall – despite living here for 10 years – never learned French.) For years the Halls had been trying to get an ambitious golf project off the ground. They wanted to turn the chateau into an 18-hole golf resort with holiday cottages. That's presumably what the file resting on the chair was all about, Mayor Sourdain says.

"It would have happened, too," he says. "They would have made it happen. That's the kind of man Robert Hall was." He pauses and says, wistfully, "It would have been so good for the region." There's a short silence. Then he says, less confidently, "I'm sure it would have happened."

On the evening of 4 September, Sourdain got a call from the gendarmes – something had happened at the château. It is a French custom for the gendarmes to call the mayor, as the representative of the people, to the scene of a crime or a terrible accident. He arrived to see the oldest son, Christopher, 22, with the gendarmes as they stood in protective suits breaking up a big block of concrete. Robert Hall was inside the house, crying.

"After 24 hours, concrete is like biscuit," Sourdain explains. We're sitting in his office in the village of Le Chatellier, two miles from the chateau. "So the gendarmes were crumbling it with their hands. And after a while they discovered a ring. They asked Christopher, 'Is this your mother's ring?' He said, 'Oui.'"

Robert Hall had told the gendarmes that 24 hours earlier he'd had a drunken argument with Joanne during which she accidently fell, hit her head, and died. Then, during the hours that followed, he set her body on fire, put her remains into a builder's bag, poured in concrete and hauled it on to the back of a lorry. All this happened behind the house, near the back gate, next to a row of half-built holiday cottages.

Then he stopped. He telephoned Christopher. He said he was going to commit suicide. Christopher called the ambulance, who called the gendarmes, who called the mayor.

Catherine Denis, from the prosecutor's office in Rennes, told a press conference later that week that when the gendarmes asked Robert why he burned Joanne's body and encased her remains in concrete, he explained that she'd always said she wanted to be cremated and laid to rest in a mausoleum and he was simply respecting her wishes, albeit in a somewhat informal way.

"What did the Halls do for money?" I ask Mayor Sourdain. "How were they living? How were they funding the golfing project?"

"He told me he was a big success in England," he replies. "He had lots of businesses there. And sometimes British tourists would rent the château for their holidays."

"Do you know if the tourists enjoyed staying there?" I ask.

"I wouldn't know anything about that," he replies, slightly tersely. "It would have been between English people. You see?"

Fabrice Fourel works in a bright office in the nearby village of Saint-Étienne-en-Coglès. Posters advertising successful Brittany tourist endeavours line the walls. I am sitting, he says, exactly where Robert and Joanne Hall sat when they came to him in a flap regarding their golf project, in September 2008.

"They were lost," he says.

Fabrice's job is to be the middle man between prospective tourist businesses and the labyrinthine French bureaucracy.

"What were the problems?" I ask.

Fabrice sighs as if to say, "Where do I begin?" "They wanted to clear some trees. French law says you have to plant three trees for each one you cut down, not necessarily on your property, but in the region." He pauses. "It was a big problem. In fact, the administration was angry with the Halls because they didn't follow the procedure. We had to calm everything."

"How many trees would they have needed to plant?" I ask.

"Around 20,000," Fabrice says.

Fabrice says people basically already have all the trees they want. If you go to people and offer them trees, they tend to say no. And that wasn't the only problem. The Halls needed sprinklers, enough electricity for thousands of visitors…

"We quickly noticed a gap between the financial needs for such a project and what they had," Fabrice says. "A project like that could cost €20m (£17m)."

"Was it a big gap?" I ask.

Fabrice indicates with his hands a very big gap.

"But they were really motivated," he says. "That's why we didn't want to say, 'You can't do it.' People have to be a bit crazy to lead these kinds of projects."

I ask Fabrice if he knows whether the Halls' business renting out the château to British tourists was a success.

"We know nothing about that," he says. "We know they welcomed people into their house. But we don't know the details."

In August 2006, Laura Walsh was looking to rent a château for her family holiday when she chanced upon chateaudefretay.com. The site is gone now, but you can still find it on the internet archive, with its photograph of horses grazing by the lake, plus a list of activities such as fishing, swimming, a games room, a go-karting stadium, cycling and a weekly treasure hunt.

Laura phoned Joanne Hall, who told her, "We're not Center Parcs, but we do our best", which Laura took to mean they were something like Center Parcs.

And so, swept up in the lovely sounding nature of the thing, she offered to pay the full amount up front – £2,600 for a fortnight's stay.

"The first thing we saw, as we walked into the bedroom, was what looked like mouse droppings on the bed," Laura says. "Robert Hall appeared in the doorway. I said, 'There are mouse droppings on the bed.' He said, 'Oh no, no, they're more likely to be bat droppings.' "

"How was he?" I ask.

"Friendly," Laura says.

She ran herself a bath and left the bathroom for a minute. When she came back, the bath was empty and the bathroom floor was flooded. They decided to persevere, and went looking for the go-karting stadium.

"We found it in a clearing in the forest," Laura says. "It was a mess. A shambles. An overgrown shambles. And in the middle of it was a dead goat."

And so on. There were live wires dangling in the outside toilet, the pool was leaking, there was rubble and broken glass everywhere, and so that evening they confronted the Halls.

"They seemed dazed," she says, "out of their depth. And drunk. They must have known on some level that this wasn't right, but instead of admitting it, there was a restrained crossness about them. Robert kept saying, 'You're just not getting it. You're not getting it. You don't get it.'"

"'Not getting it'?" I ask.

"He meant, 'You're not getting what this is about," she says. " 'You're not getting how idyllic it is.' "

The saddest thing, Laura says, was that the most clear-headed family member was Christopher, the teenage son. He was the only one trying to make everything OK. Laura negotiated with him, and they agreed to stay a week and get a refund for the second. On day two they decided to try out the games room.

"In the hall right outside it," Laura says, "propped up against the wall, was a shotgun."

"Was it loaded?" I ask.

"There was live ammunition on the shelf next to it," she says.

When they left, Laura let the tourist office in nearby Fougères know what a mess the place was. They told her they'd had countless similar reports and had been trying to shut down the place for years. It was widely known in the area, she says, that Château de Fretay was a disaster.

From August 2006 onwards, anybody Googling the château would have straight away come across Laura's startling reviews on TripAdvisor and Mumsnet: "BEWARE; CHATEAU DE FRETAY!"

The Halls' neighbours – farmers who didn't want to be named – tell me that very few tourists, if any, came to stay at the château these past few years. The Halls' income seemed to dry up, they say.

The Halls had been in France for only a year when, in 2000, Robert Hall called on Yves Bourel, a local journalist. Yves knew him by reputation, he says, as there had been some excitement locally about the family's arrival. "English people with money usually go to the south of France," he tells me. "We tend to get the poor English people here, because living here is cheap."

Yves and I are having breakfast at my hotel in Fougères.

"Why did he come to see you?" I ask.

"He had a business proposal he wanted publicising," he says. "He wanted to create a hot-air balloon port from the grounds of the château."

"Oh?" I say.

There's a short silence. "We have a lot of wind here," he says. "The balloons would have lifted off and… whoosh!" He waves his arm to indicate a hot-air balloon flying uncontrollably away.

We laugh. "Did anyone say anything to them about the wind?" I ask.

"Oh no!" he replies. "We don't see rich English people often. So we put the red carpet out for them!"

Yves asks if I've heard the news – the prosecutor has decided to charge Robert Hall with aggravated murder.

There's a beautiful double-fronted Georgian mill owner's house outside Holmfirth, West Yorkshire, with an oak-panelled dining room, low beams, marble fireplaces. The windows look out across the fields where they filmed Last Of The Summer Wine.

In front of the big Aga-type stove in the kitchen, the owner Richard Skelton tells me a story about what happened shortly after they bought the place from the bank, who had repossessed it from the previous owner, Robert Hall. Late one night – this was in 1999 – there was a knock on the door. Richard's wife, Loretta, answered. Two frightening-looking men were standing there.

"Is Robert in?" they asked.

"They didn't look like normal bailiffs," Richard says. "These were serious, hard men."

Loretta knew something like this might happen one day. They had heard stories from the neighbours. On one especially creepy occasion, the next-door neighbour had had a knock on the door in the middle of the night. The two men standing there wouldn't believe him when he said he wasn't Robert Hall. He had to get a utility bill to prove it.

"There was a trail of irresponsible behaviour all over town," Richard says. "Not paying loans back… And you should have seen the state of this place when we moved in. The pattern over and over is that people would do work for him, he wouldn't pay them, so they'd walk away, leaving everything all rough and unfinished. Wiring, joinery…"

Loretta told the men at the door that Robert Hall didn't live there any more, that he'd moved to France. Luckily, they took her word for it. As they left, one of them turned to her and said, quite cheerfully, "Oh, if you ever want someone beating up, it's £200."

Richard gives me a tour of the house. He shows me the en suite bathroom. "They had a corner bath in here," he says, "which was an utter disaster. It was cracked, leaking. The chap who put in the new toilet says it's amazing any waste got out of the old one."

He pauses. "Everyone says Robert was a very closed person," Richard says. "He was very sociable and charming, but after a conversation with him, you'd walk away realising you'd learned nothing."

"What was Joanne like?" I ask.

"She was considered to be lovely and charming," he says. "A neighbour said that regular as clockwork she'd go blasting past the houses in a battered Porsche taking the kids to school at five past nine. Everything was always chaotic."

I stop off at the local ironmonger's store, JW Kaye, to test Richard's story about Robert Hall leaving debts all over town.

"Yes, he owed me money," says Dave Earnshore, who runs the place. "But it wasn't much, so I didn't think it was worth pursuing. He owed a lot of other people a lot more money than he owed me when he disappeared out of sight."

"To France?" I say.

Dave shrugs: "I suppose."

He reels off a list of failed Robert Hall businesses: a kitchen place in Dewsbury, a fitness centre, an abandoned golf-resort project in Derbyshire, a company that imported cars from Europe and (illegally) adapted them from left-hand to right-hand drive, a disastrous Santa's grotto in the farmers' market in Hollowgate.

"He told Kirklees council he was going to make it Christmassy and lovely, like a fair," Dave says, "but when it opened it was just a stall selling cheap plastic crap."

When the council shut it down, Robert Hall smashed his way back in with a baseball bat.

Man selling festive gifts is closed down

…Security guards are patrolling the former Castle garage in Hollowgate and Robert Hall has been given until the end of the month to remove his property. Mr Hall admitted he broke in and continued to trade for two days after the locks were changed by the council. Councillor George Speight, who chairs the council's markets committee, said, "In our opinion this was a market and not a fair."

– Huddersfield Examiner, December 1993

"He always had big plans that were always…" Dave pauses. "…crumbling."

A few hundred miles south of the Château de Fretay, in the countryside near Cognac, Maria-Louise Sawyer runs a support group for British people who've moved to rural France to try to live the Year In Provence-type dream, only to find the whole thing spiralling out of control.

"It's the same story time and again," she says. And then – with a quite chilling fluidity – she tells me the "story":

"The French like to live in little tiny modern bungalows. When they inherit these big old properties, they don't want them. So they sell them cheap to the British. Back in Britain, the man was working, the lady was home. That was fine. They saw each other for only a couple of hours in the evening and at weekends. But then they move here. These are larger properties with grounds. So they're isolated. They can't speak the language. The man is possibly renovating an old property, but he doesn't know how to do it. Everything is different. You go to a government office, you don't speak French, you're an outsider. So he gets more and more isolated and resentful. He and his wife are together all the time. And they realise they don't like each other. They drive each other bonkers. They drink, because the drink over here is less expensive than water. And then… bang."

Maria-Louise pauses. "That's what happened with my husband. He buggered off back to Britain after shredding all my clothes, daubing food over the walls and leaving a note that said, 'I've gone.'"

The day Joanne Hall died, some neighbours saw her in the garden. It was the last sighting of her. She was pruning the trees and gardening – starting to plant the hundreds of seedlings in the plastic cups on the table that are still there, but all dead now. The neighbours say she looked up at them and, with a big smile, waved.