To the outside world, Mitchelswood Farm is a haven where children learn to ride ponies amid 20 unspoilt acres of idyllic countryside.

The family-run farm has gained a loyal following with its relaxed, friendly atmosphere, professional staff and exemplary standards.

But beneath this respectable veneer runs a long and bitter dispute between a man and his ex-wife over ownership of the farmhouse at Newick, near Lewes.

Under normal circumstances, such disputes would be settled within the family. But, as a judge put it, this was a "somewhat unusual case".

It ended yesterday with computer consultant Derek Lightfoot losing his High Court bid against his former wife, Seona Lightfoot-Brown, to regain a share of the farmhouse.

Mr Lightfoot lived at the farm with his first wife but in 1985 he bought her share of it and subsequently moved Mrs Lightfoot-Brown in.

Between 1988 and 1992 they had three children and married in April 1993 but the marriage fell apart and divorce proceedings began soon afterwards.

A decree nisi was granted in June 1994 but the couple reconciled their differences and had a fourth child. They subsequently fell out again and proceeded with the divorce in 1996.

Yet again, the pair were reconciled and until September 1998, when their marriage finally broke down, they continued to live at the farm.

Mr Lightfoot signed away ownership of the farm to Mrs Lightfoot-Brown in 1997.

Judge John Martin, QC, told the court Mr Lightfoot made mortgage payments of £24,000, a capital payment on the mortgage of £41,000 and also spent money on a stable unit and a new kitchen.

Because he had ploughed such vast sums into the farmhouse, Mr Lightfoot claimed he was still entitled to a half-share of it.

Mrs Lightfoot-Brown rejected his claim.

What ensued was the expensive and damaging High Court case which ended with Mr Lightfoot on the losing side yesterday.

Richard Jones, QC, for Mr Lightfoot, said he made the payments only because he believed he was going to receive back a half-interest in the house.

The barrister argued Mrs Lightfoot-Brown made the promise at two separate meetings but she said there was "no firm agreement".

Judge Martin rejected Mr Lightfoot's arguments because there was not an "understanding or agreement" for him to regain a share.

After listening to lengthy legal arguments, the judge said although he had "not found it easy to resolve these conflicts of evidence" he preferred Mrs Lightfoot-Brown's testimony.

Judge Martin said the clear implication of Mr Lightfoot's evidence was that the redistribution of property was conditional on the couple remarrying.

He also said a number of documents written by Mr Lightfoot or on his behalf appeared to contradict his account.

After the case, Mrs Lightfoot-Brown said the result felt like a hollow victory.

She said juggling the responsibilities of running a riding school, caring for her daughter and three sons and paying legal bills for such a long time had taken their toll.

Mrs Lightfoot-Brown said she set up the riding school as her failing marriage was dragged through the courts.

She said: "I could see where all this was going and I started up the riding school. It was always my love. I've always been a 12-year-old pony girl.

"The stress levels were just unreal. I'm only coming back down off it now.

"With all the kids on holiday and as everyone's laughing and playing about, it's beginning to sink in that this life I have can carry on.

"I built this business from nothing. I've got waiting lists for people wanting to come here and I want to build a new barn but all the money has gone to the lawyers."

After their divorce, Mr Lightfoot remarried and moved to Italy while Mrs Lightfoot-Brown lives at the house and stables with new husband Keith Brown.

Mrs Lightfoot-Brown said she tried to keep her children sheltered from the battles as much as possible.

She said: "I allowed my two eldest to be privy to it but I kept out the gory details."