A French Jewish woman won a court victory this week after a judge granted her custody of her daughter, who she claims had been held captive by the girl's Saudi royal father.

But Candice Cohen-Ahnine, 34, is unable to celebrate because Prince Sattam al-Saoud has refused to comply with the ruling, which also demands monthly child support of £8,300.

Aya, ten, remains in the Riyadh palace, where Ms Cohen-Ahnine says she has been kept for three and a half years and brought up as a devout Muslim.

The child was born in 2001, four years after the couple met in a London club. Ms Cohen-Ahnine, who has written a book about the fight for her daughter, has recalled that she was showered with champagne and expensive gifts and taken on luxury holidays by the "tall, dark stranger".

The relationship continued, with the prince regularly visiting Paris. But when their daughter was five, she said she was told by the prince that he was expected to marry a cousin and that she could be his "second wife".

She declined but says she continued to involve him in Aya's life, bringing the girl to the palace in 2008. However after being given only minimal access to Aya during the stay and prevented from leaving herself, she says was forced to flee the country and has not seen her daughter since.

According to Ms Cohen-Ahnine, even though she was born Jewish the prince produced a document claiming that she had rejected Islam to convert to Judaism – something that could mean a death sentence in Saudi Arabia.

Ms Cohen-Ahnine has spent the last few years urging the French authorities, including the foreign ministry and President Nicolas Sarkozy, to help her

The prince has vowed to ignore the court's decision, reprtedly telling Nouvel Observateur magazine that he would "hide in the mountains" like Osama bin Laden rather than accept it.

"My child's life is here," he was quoted as saying. "Let me remind you that my daughter is a descendant of the Saudi royal family." He also told the Telegraph that Ms Cohen-Ahnine's story was false and said she had converted and married him under Islamic law, and left Saudi Arabia of her own accord.

He now faces an international arrest warrant for ignoring the verdict.

Miss Cohen-Ahnine said she was pleased with the ruling but aware that it was not the end.

"It vindicates everything I have said ... but I'm still very worried for my child's future," she said.