The woman who told police she was raped by Pippa Middleton's father-in-law has been praised by her father for having the 'courage' to come forward.
He said his daughter, now 36 but 15 at the time of the first alleged offence, told him she is deeply upset by what she sees as an attempt to cast her as a fantasist, reports Daily Mail.
And he described suggestions she was trying to humiliate David Matthews, 74, just months after his financier son James married Prince William's sister-in-law, as "ridiculous".
In an exclusive interview with The Mail on Sunday, the woman's father said: "The idea that she is doing this for compensation, or for any other reason than a desire for justice, is completely wrong."
His daughter, who is British but cannot be identified for legal reasons, told French police last year that she initially blamed herself for the alleged attacks, which left her feeling "shocked and disgusted".
One of the offences is said to have taken place on the Caribbean island of St Barts, where Mr Matthews, a former racing driver, owns the £5,000-a-night Eden Rock hotel.
The second attack allegedly took place in Paris.
The Mail on Sunday understands that the woman told police she was first groomed and assaulted when she had just turned 15 but that the first alleged rape took place when she was 16.
Mr Matthews has vehemently denied the claims.
His accuser, who is unmarried, first confided in her parents three years ago, and her account left them "incredibly shocked".
Her father said: "She told me, 'You don't know what I've been going through all these years.'"
"Then it all came pouring out. She said it had been a burden because she had kept it bottled up for so long.
"It's caused her an immense emotional strain. She's been unable to form any lasting relationships."
Mr Matthews was stopped at Paris Orly airport last month after he flew in from St Barts, a French dependency, where he lives with his wife Jane.
He was held for 48 hours and questioned before appearing at the Palais de Justice, where he was charged with the "rape of a minor by a person with authority over his victim", a crime that carries a maximum 15-year jail sentence in France.
Initially, the woman's father felt that a criminal investigation and possible trial might prove too emotionally damaging for her.
But while he still harbours concerns – "as any parent would" – he said his daughter is resolutely determined to seek justice and is prepared to face Mr Matthews in court.
Last week a source close to the Matthews family told The Mail on Sunday that his accuser was being "assisted" in her complaint by her mother.
"I've heard the full story. It's outrageous," said the source. "I feel very sorry for David. He's completely being set up just to cause family embarrassment."
But speaking at his spacious home in a quiet village, the woman's father issued an impassioned defence of his second-born child.
Softly spoken and possessed of unusual equanimity, his face only betrays anger when he responds to the claims from the Matthews camp.
He said: "The family are furious about what is coming out from the Matthews side since she came forward as she is being made out to be a fantasist and having made it all up.
"What could possibly be her motivation for revenge or embarrassing the Matthews?
"We are all behind her and believe her. She had the courage to speak out – and she did, and by doing so she feels she can give herself some sense of closure."
The father, who has been interviewed by French police and given a statement, declined to discuss details of the case beyond saying that his daughter told police the first attack happened while she was on holiday in St Barts.
He spoke as it emerged that a second woman has come forward to accuse Mr Matthews of rape.
Believed to be a former family friend, she reported her claims to South Yorkshire Police last week.
Now thought to be in her 60s, the British woman is said to have accused the tycoon of assaulting her in Sheffield in the 1980s, when she would have been in her 20s or 30s.
Detectives must now assess the strength of her allegations before deciding whether to arrest Mr Matthews, interview him under caution, or drop the case.
Mr Matthews's official status with prosecutors in France, meanwhile, is "mis en examen", which is widely considered to be similar to being charged in the UK, although there is no exact equivalent in the British legal system.
He has since been released on bail and has been told he can leave the country, although he is expected to return to Paris as the investigation continues.
Authorities have up to six months to decide whether he should stand trial or to drop the charges.
French investigators say they were 'being kept up to date with developments in Britain' related to the second Matthews case.
A spokesman for Mr Matthews, who is represented by the Queen's solicitors, Farrer & Co, said: "David Matthews categorically denies the allegation and unequivocally contests the untrue and scandalous accusation."
A friend who has known Mr Matthews for decades said the rape allegations were completely out of character.
David Zara said: "David is not that sort of person and he is certainly not a rapist and certainly not a child molester."
Mr Zara, who runs bespoke charter flight service Air One, said he believed his friend was the victim of a woman seeking revenge.
He said the Me Too movement, established in the wake of the Harvey Weinstein sex abuse scandal, had made it 'hunting season on powerful people'.
Mr Zara added: "I have known David for 20 years and I know him pretty well. I think it's… revenge."
A friend who works with Mr Matthews and his wife said: "It's an extraordinary claim. I think it's just a misunderstanding. Everybody is just shocked here about it."
Born the son of a coal miner in Rotherham, David Matthews managed to amass a reputed £40 million ($77.5M) fortune.
He also gained the title Laird of Glen Affric, while his children have millions of pounds of their own.
In his younger days he tried his hand at motor racing, and was seen as promising until he was in a serious crash at Silverstone.
It left another driver dead, and Matthews with an eye injury that ended his racing career.
Instead, he concentrated on building his own second-hand car empire, with motor dealerships and interests in luxury coach-making.
His first marriage was to Anita Taylor, herself a racing driver. They had a daughter, Nina, but later divorced.
By the Nineties, Matthews had made enough to start serious property development.
He married for a second time to bohemian artist Jane Parker, now 70, daughter of an architect in what was then called Rhodesia.
She had been carnival queen at Rhodes University in the African country, now Zimbabwe, and after graduating with a fine art degree won a scholarship to study in the Netherlands.
After stopping off in London on her way there, she never left.
After marrying the couple moved to Paris, then to tax-haven Monaco. On holiday in 1995 they loved the faded glamour of the Eden Rock hotel on the Caribbean isle of St Barts so much that they bought it.
They moved to the French- speaking island and restored the hotel, a favourite of celebrity guests including Sir Elton John and Beyoncé.
Pippa Middleton married David Matthews's son James last summer.