The ex-wife of a Saudi billionaire has told a family judge her multimillion-pound divorce claim is "not unreasonable".

Former supermodel Christina Estrada, 54, said at London's High Court that the award she is seeking reflects the standard of living she enjoyed during her marriage to Sheikh Walid Juffali.

The court heard details of the couple's lavish, globe-trotting lifestyle.

But lawyers for the sheikh have described her post-marriage budget demands as "excessive, exaggerated and firmly in gasp territory".

In a case that could result in one of the largest divorce awards in British legal history, Ms Estrada's lawyers are arguing it is the 61-year-old sheikh's assets and lifestyle which have the so-called "gasp factor" and justify her claim that she is only seeking to cover her "reasonable needs".

They contend Dr Juffali's offer would leave Ms Estrada, 54 - his second wife and mother of one of his six children - some £37 million in cash and assets, and that was "clearly inadequate".

They estimate Dr Juffali's wealth at over £648 million, including a UK property portfolio of more than £140 million.

According to documents before the court, Ms Estrada is seeking a "clean break" award of over £196 million.

The ex-wife is also seeking a declaration that she is the owner of a blue diamond ring.

Dr Juffali said he bought the ring for 4 million US dollars (£3 million) as part of his collection and it was not given to Ms Estrada, but he has now given it away to a third party.

The sheikh, an international businessman who is seriously ill with cancer and undergoing treatment in Switzerland, divorced Ms Estrada in Saudi Arabia in 2014 without her knowledge after 13 years of marriage.

She obtained leave under Part III of the Matrimonial and Family Proceedings Act 1984 to apply for financial relief in England because she could not bring a case in Saudi Arabia.

Dr Juffali attempted to block her application on the grounds that he was entitled to legal immunity because of his diplomatic status as permanent representative to the International Maritime Organisation (IMO) of the Caribbean island of St Lucia.

But the Court of Appeal ruled he was not immune as the divorce claim did not relate to his diplomatic duties.

Lawyers for Dr Juffali argue that he is being wrongly portrayed as "the villain", but he has bought his ex-wife a luxurious house in Beverly Hills and is largely responsible for her being "a very wealthy woman" who already has assets of over £20 million, sufficient to meet the needs of any 54-year-old woman.

The lawyers say Dr Juffali is willing to go further and is offering her a £17 million cash payment over five years and the use of a luxurious £6.5 million home in London, in their daughter's name, for the next five years while meeting all associated costs.

He is also meeting the £150,000 annual expenses and education costs of their daughter.