Thousands of Brits move to France every year. They come for many different reasons – the climate, the food, a higher standard of living, the comparatively cheaper housing. But all of them have one thing in common: they come here for a better life. None of them imagines they will end up dead at the bottom of a lake.

When Evelyn and Robert Lund moved from Lancashire to a 400-year-old farmhouse in the Tarn region of southwest France 10 years ago, they were pursuing just such a dream. Evelyn, whose first husband Arthur, a building society manager, had died of lung cancer, leaving her a wealthy woman, had fallen for the charms of Robert Lund, a tree-feller.

Her children disapproved of the match, not least because Lund was living in a caravan when they met. But they settled – at first happily – into the small expatriate community. Lund loved his new role as “lord of the manor” and his grand, lavender-filled garden. His wife relished the wine and sun.

But slowly things began to unravel. Evelyn was drinking too much and the marriage fell apart. Lund was a womaniser – some even suspected he was a wife beater.

Then the unthinkable happened. On December 29, 1999, Evelyn disappeared. Her husband claimed she had stormed out of the house after a row and he had never seen her again.

Her body was found two years later, on October 13, 2001, at the bottom of Lake Bancalié, 15 miles from her home in La Veaute. The water in the lake had dropped by 30ft due to a drought and the roof of her red Toyota Land Cruiser had been spotted by a passing horse-rider. A ghastly accident, suicide or foul play?

The “lady in the lake” case has transfixed – and divided – the local community ever since. Last week, in the cour d’assises (criminal court) in the medieval city of Albi, Robert Lund was cleared of murder but convicted of Evelyn’s involuntary homicide, which means the jury did not accept he intended to kill her. He was sentenced to 12 years in prison.

Even in court, Lund cut a dash with his fuchsia shirts and silk handkerchief peeping out of his pocket. Despite the guilty verdict, many people in the area believe he is innocent and the two factions – Evelyn’s friends and family and Lund’s local supporters – sat on either side of the packed courtroom, like guests at a wedding.

The person who knew them best was Marianne Ramsey, 61, who introduced herself when she heard the Lunds speaking English in a cafe in Realmont just after they arrived. At that time the expatriate community was small enough for everyone to know each other and newcomers were welcomed warmly.

The couple quickly became friends with Marianne and her husband Alan, but Marianne soon began to have reservations about Robert Lund.

“It became apparent very quickly that Evelyn was an utter delight,” says Marianne, “and that he was utterly ghastly. He was so full of himself, always putting her down. He thought he was God’s gift to women. He was constantly sniping at her.”

The couples remained friends for some months but, for Marianne, one sunny day Robert went too far. They were having lunch by the pool. “Robert insisted we all go skinny-dipping. I refused – Alan doesn’t swim – but Robert made Evelyn strip. It was humiliating, for us as well as her.”

Marianne may have been the last person to see Evelyn alive.

“She showed up at my house on that December day in a state of high agitation. I could hardly make out what she was saying. We calmed her down and gave her lunch,” says Marianne.

“She had three glasses of wine, nothing excessive. We talked about her relationship with Robert. I again told her to leave him. I had been saying the same thing to her for months.”

Marianne maintains that Robert wanted to get Evelyn away from her family, who disapproved of him, hence the move to France. “The French move was never her dream, she never learnt the language or really settled. But she loved the space for her animals and she was a great cook, always making jams and Lancashire hotpot,” says Marianne over lunch outside the court.

Evelyn’s daughter Victoria agrees. “My mother always dreamt of moving to Scotland,” she told the court. “He moved her here to isolate her from her family and friends.”

Views about both the Lunds are so entrenched that it is difficult to determine exactly what did happen the day Evelyn disappeared. After lunch that December day, Marianne suggested they all have a siesta and then talk over Evelyn’s situation with Robert.

She showed Evelyn to the spare room and left her there. When she awoke an hour and a half later Evelyn was gone, leaving a note on kitchen paper: “Gone to feed the animals. Evelyn x”.

Marianne thought no more of it: “It was totally normal for her to put her animals first and she never trusted Robert to feed them,” she says.

The court heard from the defence that Evelyn never made it home from lunch at Marianne’s. Before leaving Marianne’s house Evelyn made two telephone calls. One was to her husband, the other to Diana Hsu, another local friend.

“She asked me to come and get her because she’d had too much to drink,” says Diana. “I said no because it was such a wild stormy night. I was the last person to speak to her.”

The drive from Marianne’s home in Montdragon to Evelyn’s house in the hamlet of La Veaute takes about 40 minutes. To get home Evelyn had to drive round Lake Bancalié.

“She had driven that way hundreds of times, there is no way she would have taken a wrong turning,” says Marianne. “And anyway her glasses, which she was wearing at our house, were later found in her handbag in her home. And she had changed her clothes.”

Much of the case against Robert Lund hinged on the glasses and this change of clothing. If Evelyn had gone home before she ended up in the lake, chances are that he killed her, as the court concluded.

“I think she got home, they carried on the argument, he hit her, maybe she fell and hit her head on the fireplace or something, and he put her in their car, drove her to the lake, left her there and cycled home,” says Marianne.

The police also found it suspicious that it took Lund three days to report his wife missing after she had vanished. He said he thought she had gone to visit her family in England. A huge search followed, with more than a hundred police officers digging up the couple’s farm in search of a body. But for the water levels in the lake falling dramatically during the drought in 2001 she might never have been found.

When they searched her Toyota, traces of blood were found on the back seat and tests on her body showed when she entered the water she was no longer breathing, which indicated that she had been smothered or knocked unconscious first.

But Lund’s supporters still believe it is impossible that he could have killed his wife and there has been a miscarriage of justice.

“While the rest of us were into cricket and football, Robert was into gardening. He was a gentle lad and would never harm anyone,” says his brother, Neville Lund.

Diana Hsu, disturbingly, maintains that Evelyn was the violent one in the relationship. “I remember once Robert had to protect her five-year-old grandson by lying against his bedroom door because Evelyn was on the rampage. She was a lovely woman until she got drunk and then she became another person.”

It would not be an extraordinary turn of events. For many British expats alcohol is one way to fill the long days and cold winter nights. Dawn Alderson, the head of the French law department at Russell-Cooke solicitors in London, says she has seen the dream turn sour many times.

“People go with unreal expectations of what it’s really like. It is not like a little England, it is France and many people,women especially find it hard to adapt. They come not speaking the language, with the same set of problems and they don’t have the support network they have at home.”

Hsu says she spoke to Evelyn on Christmas morning, just a few days before she disappeared. “That year, we were supposed to be making Christmas lunch together,” says Diana. ” She was upset because none of her children was coming to stay so I wanted to cheer her up.

“Christmas morning I get a phone call. It’s Evelyn and she’s drunk. ‘What day is it?’ she asked me. I told her it was Christmas Day. ‘In that case,’ she said, ‘I will have to apologise to Robert’.”

The case has been the talk of the British set for months. Despite the verdict, some will always find it impossible to believe Lund is guilty. But it may be that the real cause of the crime was the despair that sets in during a long winter in la France profonde, when it’s Christmas and you are a long way from home.