The ex-girlfriend of Prince Andrew has lost a multi-million-pound High Court fight with an old flame after claiming she had been promised financial support for the rest of her life.

American photographer and actress Koo Stark, 63, claimed financier Warren Walker had pledged in 1997 to give her £50,000 a year, in exchange for her dropping the idea of writing a tell-all newspaper column.

Ms Stark, who dated Prince Andrew in the Eighties, relied on a handwritten note as she sued Mr Walker, saying he had only paid two annual instalments after their relationship ended. She also said he had failed to honour a promise to give her £200,000 for a new home.

Mr Walker, 60, branded Ms Stark a “gold-digger”, denying that they had been formally engaged and arguing his promise had not been legally binding.

Following a High Court trial in private, Judge David Halpern QC has thrown out Ms Stark’s claims and published his judgment in the case. He said the 1997 promise of £50,000 a year was more like a “gentleman’s agreement” between the couple, who have a daughter. “It would not be an exaggeration to say that the parties disagreed on almost everything, save for the fact that they each clearly love [their daughter],” he said.

The former couple met in 1994 and lived together in Knightsbridge. Ms Stark claimed she had been in negotiations in 1996 to write a column for The Times called Diary of A Single Mother.

She argued that Mr Walker found the idea “distasteful and unethical”, and had promised her “equivalent of £50,000” a year to stave off the column during a second round of negotiations in 1997.

However, Judge Halpern stated in his judgment: “If Mr Walker had indeed made a binding agreement to pay her this sum in return for forgoing the opportunity to write for The Times, I would have expected him to have recorded this in the document. I am not satisfied on the balance of probabilities that the opportunity to write a column for The Times was revived in 1997, nor that it was turned down in consideration of Mr Walker agreeing to pay her the sums set out in the letter.”

He said Mr Walker intended the letter “to be nothing more than a ‘gentleman’s agreement’, using that term in the ironic sense,” and noted that there was no mention of how long payments should continue.

However, the judge also said that “it was clear to me that there were occasions when [Mr Walker] did not tell the court the whole truth”.

Mr Walker paid Ms Stark the equivalent of £50,000 a year from September 1997 to the end of 1999. In the court case, she said the couple had been engaged three times; Mr Walker argued it was more an “informal” agreement.

The judge ruled a 2001 promise from Mr Walker to give her £200,000 to secure a home in the UK had been made in family court proceedings. Details of the ruling can now be published after a bid by Ms Stark for reporting restrictions was rejected.