Gillian Turner put $261,000 of her life savings into setting up a home with Michael Durant, a court heard, and sold her house.
The property developer is said to have wooed the former receptionist and told her they would be “together forever”.
Miss Turner, who had a child with Mr Durant, 61, says her investment allowed him to free up funds to grow his business and buy a “valuable” string of buy-to-let properties, stretching from the home counties to Leicester and Darlington.

Michael Durant has been dragged to court for failure to keep his love and financial promises

The couple split in 2014 and she has now taken him to court, claiming he reneged on a promise made in the kitchen of their $1.44 million family home in Hertfordshire to “give her” half of a business which she says may have been worth millions at the time.
Turner said she was working as a receptionist for a timber firm in 1989 when she met the playboy businessman and the “stormy relationship” between the pair began, with him making a series of late night visits to her home.
“He would turn up at 2.30 in the early morning after the nightclubs had shut, knocking at my door and asking to be let in,” she told the court.
“He would stay with me a day here and a day there but it never worked. He just kept wanting to go nightclubbing every weekend.

Michael Durant [left], defending his business against claims of 50 percent share of assets filed by his ex Gillian Turner [right]

“The relationship was always on the rocks. He would stay for a few days and I would live in hope that it would be good this time,” she said.
She added: “But as soon as another friend wanted to go on holiday or clubbing he would be off again.
“Then around Christmas Eve 1998 he turned up, telling me how much he loved me and how he wanted to start a relationship and how he really meant it this time,” she said, telling the judge that the couple’s son was born soon after in 1999.
“But the pattern didn’t change after our son was born. He was just never there. He would turn up from time to time saying he wanted to see his son,” she said.
Then, in 2004, Miss Turner said, Mr Durant persuaded her to put up the $261,000 deposit for them to buy a family home together in Hill Rise, Cuffley, Hertfordshire, now worth about $1.44 million.
She told the judge Mr Durant promised her a 50 per cent share in his business but said that after they split in 2014 he had refused to give her half of his company, Lodge House Ltd.

The multi-million dollar home in Herts, UK which former receptionist Miss Turner shared with property tycoon Mr Durant

Instead, she claims she was “fobbed off with 50 per cent of the shares of another company which was not as valuable”.
At this point, Judge Alan Johns asked the plaintiff: “You don’t know if [the business] is [worth] $10 or $1 million, all you can tell me is that your claim is a valuable one, but you are not sure how much,” the judge noted.
But Gary Cowen, Durant’s attorney, told the judge that there had been no agreement to share Lodge House Ltd with his ex, and that he owed her nothing, having in effect matched her contribution to buying the family home by paying the mortgage.
“You were putting in $26100,000 and he was effectively putting in $328,000 by agreeing to pay the mortgage. That was his contribution to the purchase price,” he said.
In evidence, Mr Durant said that he has forked out about $236,000 in mortgage payments on the family home, and that $216,000 remains outstanding on the property, which the former couple still own jointly.
He added that the “frequently stormy” love affair between himself and Miss Turner “was a relationship that had its ups and downs,” but denied making any promise to cut her in on Lodge House Ltd.
Judge Alan Johns has now reserved judgment to a later date.