She is the secret daughter of Princess Diana with Prince Charles, it’s unreal how she was conceived

It’s the secret they have so desperately tried to keep hidden. But as the royal family prepares to celebrate Prince Charles’ milestone 70th birthday, a dark conspiracy theory about Princess Diana is set to be revealed.

Rumours surrounding the possibility of the late princess giving birth to a secret daughter have been swirling for years, but as Prince Charles prepares to celebrate his birthday this week, it looks as though those rumours are set to resurface – an event that has left him and his wife Camilla Parker Bowles furious.

For a number of years royal insiders have heard wild rumours that Diana gave birth to a girl called Sarah, who is now in her 30s and is said to be older than Prince William, 36.

According to US magazine Globe, before she married Charles in 1981, the then 19-year-old Lady Diana Spencer was ordered by the Queen to undergo gynaecological tests to establish that she was capable of bearing children before her engagement to the heir to the throne could be announced.

The outrageous story claims that Diana’s eggs were harvested and then fertilised with Prince Charles’ sperm.

However, after the tests came back and Diana’s fertility was deemed to be healthy, instead of the embryos being destroyed, a “rogue doctor” secretly held onto them and implanted them in his own wife, making her the unwitting surrogate mother of Diana and Charles’ biological child.

Although the story has been dismissed as a preposterous rumour, the fact it’s doing the rounds again – and at a time when the limelight should be solely on Charles – has left a jealous Camilla furious.

“Camilla can’t believe that this story has reared its ugly head again on the eve of Charles’ 70th birthday,” says a source close to the duchess. “She’s absolutely furious.

Without a baby girl of her own, Diana formed a strong bond with goddaughter Mary Wellesley, now 31.
There have been rumours about Charles and Diana having a secret daughter for years, but for it to come out now is just infuriating for Camilla.

“Once again Diana’s name is on everyone’s lips and Camilla’s name is getting dragged through the mud. Camilla feels like she’s only just recovered from the fallout from the 20-year anniversary since Diana’s death – her popularity ratings really took a hit, and she feels like it’s happening again.”

While the rumours of a secret daughter are almost certainly unsubstantiated, there’s no denying that Diana always longed for a little girl.

Without a baby girl of her own, Diana formed a strong bond with goddaughter Mary Wellesley, now 31.

Despite her fierce love for her sons William and Harry, the princess often told friends that she secretly dreamt of having a daughter.

“Diana always wanted a girl, and she shared the joy of her colleagues and friends when their kids were born,” Patrick Jephson, the late princess’ former private secretary, told People.

“Both my daughters were born when I was working with Princess Diana, and she more than once said how lucky I was to have girls,” he added.

Although the princess sadly never realised her dream of having a daughter, throughout her life she remained close to her 17 godchildren – 10 of whom are girls.

In particular, Diana is believed to have formed a special bond with Lady Mary Wellesley. Now 31, Lady Mary possesses both her godmother’s beauty and razor-sharp brain, having studied English Language at Oxford University before going on to become a freelance writer.

Her sister-in-law is supermodel Jemma Kidd, and Mary herself has posed nude twice – once mermaid-style – for the portrait artist Howard Morgan, a risqué act that would no doubt have appealed to Diana’s mischievous sense of humour.

In the implausible story about Diana’s “secret daughter”, Globe reports that the young woman named Sarah – allegedly born eight months before Prince William – is now said to be 37 and would technically be second-in-line to the throne after Prince Charles.

The magazine claims to have spoken to Sarah, who told them that when she was growing up, she was always being told that she was “a dead ringer” for Diana.

And in a further bizarre twist, it’s even claimed that Duchess Kate has secretly met up with Sarah – a rumour that will no doubt only prove to further anger a jealous Camilla.

“Everyone should be talking about Camilla and Charles’ next steps to the throne and his milestone birthday,” spills the source. “But instead it’s all about Diana and their supposed secret baby. It’s just the worst timing for this scandal.”