Con-woman made bizarre Royal Family claim as part of disturbing plot to trick her own son into believing she had terminal cancer

For 45 years of his life, Michelin star pastry chef Graham Hornigold had lived without a mother.

Born in Germany before his alcoholic, abusive, army veteran father moved him to the UK, he'd only ever known that his mum had left when he was a baby and had never since gotten in touch.

It wasn't until Graham's own wife - fellow pâtissier Heather Kaniuk - fell pregnant with their first child in 2020 that Graham felt compelled to deep-dive into his parentage. So, with plenty of time afforded to them by the national lockdowns, the couple began their search.

Despite being confronted by several dead ends, Graham was blindsided one day to receive an email from a woman named Dionne - known formerly known as Theresa - who claimed to be his mother.

Even more shockingly, Dionne disclosed to the couple - not only that she was the owner of several global enterprises - but that she'd inherited a mass fortune, being the alleged illegitimate daughter of the former Sultan of Brunei.

Little did Graham know at the time, that in the months that followed, Dionne would rob the chef of a staggering six-figure sum and leave him picking up the pieces of yet another broken parental relationship.

The heartbreaking story is now being told as part of a brand new Netflix true crime series titled Con Mum, which landed on the streaming service on today (25 Mar).

Graham Hornigold didn't meet his mother for 45 years (Netflix)

An instant bond

In Graham's own words, their first meeting couldn't have gone better.

"The feeling I had when I first met her was - not to be a baby - but it felt like I was someone's baby," he explains in the feature-length doc. "As a child, you've never had that mother-child bond. But it becomes instantaneous from the second you see each other."

The next few months were bliss for the chef. Not only did Dionne welcome her into her exponentially wealthy life with open arms, but she did so to Heather, too - and later, their son.

She bought the pair plush cars - a Range Rover and a BMW - paid for expensive hotels, and treated them to luxury, designer gifts.

Sadly, however, Graham's joy was short-lived after Dionne broke the news to him that she had been diagnosed with terminal cancer, and had only a matter of months left to live.

Dionne claimed, however, that she wanted to ensure a secure future for her family, and invited Graham to Switzerland to meet with a series of bankers who'd handle the movement of her finances into his account after she's passed.

He travelled overseas, leaving Heather to care for their then-newborn son on her own.

Whilst in Zurich, the pair had several meetings with prolific Swiss financiers, as well as a number of business owners - the companies into which Dionne had seemingly invested immense wealth.

Heather began researching Dionne's background (Netflix)

Red flags

Despite ceaselessly conversations over inheritance, Heather became suspicious from at home in the UK when Graham revealed several weeks into trip that he was yet to sign any official documents.

Another concern was the fact that Dionne had apparently met with a number of her son's chef friends, secretly offering them millions of pounds worth of cash if they're first able to transfer her several thousand euros first.

One friend, Juan, admits in the documentary: "I told her, 'I don't have money today to give you. I'm a normal person living a normal life'. So, that thing for me, rang the bell."

It was also around this time that Heather noticed several irregularities in her own accounts, with thousands of pounds having been transferred to Dionne.

After Graham raised the question with Dionne with his wife's encouragement, she claimed several banks in Asia had put a stop on payments due to the Covid-19 pandemic.

Whenever he probed her further, Dionne turned the conversation back to her cancer - even going as far as to send photos of a blood-soaked toilet to Graham when she sensed he was becoming suspicious.

Dionne had claimed she was related to royalty (Netflix)

A shocking revelation

Heather began researching Dionne's background after it became apparent that she and Graham had transferred over as much as £300,000 - only to discover she was far from the Royal Family member she claimed to be.

She also found that she'd previously served time in jail for fraud. In fact, not only was her father listed differently on a number of official documents, but her birth date didn't add up either.

Armed with Juan's account, Heather confronted Graham with what she'd found.

Devastated, he asked Dionne outright whether she was a con-artist. Despite denying it, he subsequently found a bottle of red food colouring in her belongings, believing she'd used it to forge her cancer case.

In the documentary, Graham also discovered that she'd borrowed money from a number of business people on the basis of her using the cash on cancer treatment, but had instead spent it on champagne and hotel stays.

Finally, he decided to do a DNA test to check whether or not Dionne truly was his mother.

Graham was forced to cut ties with Dionne (Netflix)

Surprisingly, the results ruled that she was.

"She lied," Graham explains in the doc. "And I made life-changing decisions based on that. I've made choices that have affected my partner, my son."

Ties cut

With the knowledge that his own parent had conned him out of both funds and a relationship, Graham made the difficult decision to cut contact with Dionne - no longer referring to her as 'mum'.

"No mum should come into someone’s life and do that," he continued. "I was sideswiped by a seasoned pro who also happens to be my mother."

Graham also opted not to press criminal charges against Dionne, nor has she faced any criminal charges relating to the allegations presented in the documentary, it states.