A British-born Australian engineer now claims as the lovechild of King Charles and Queen Consort Camilla, it is devastating to see the former Duke of Cambridge William named Prince of Wales.
According to the Daily Mail, Simon Charles Dorante-Day, 56, of Queensland, alleged that his adoptive grandmother confided to him on her deathbed that he was the royals' secret son.
Dorante-Day was born in Portsmouth, UK, on April 5, 1966, was adopted at eight months and later moved to Australia with his family.
Both of his adoptive grandparents worked for Queen Elizabeth and Prince Philip in one of their royal households.
"It's hard not to take Charles naming William as the Prince of Wales as anything other than a kick in the face," he said.
He added, "I don't want to feel that way, but I do. I just think, the least Charles can do is give me an answer - acknowledge me. He gives William a title like that, well where's my answer? Where's my DNA test? If you are not my father, then prove you're not".
In the past years, Dorante-Day has in futility, urged the royals to submit to a DNA test to prove his heritage.
He reiterated his commitment to pursuing legal action to get King Charles to submit to a paternity test.
He had sought senior legal advice after his letter to the late Queen Elizabeth regarding his parentage went unacknowledged.
"There has been a discussion in there between a judge and me and his barrister about the legal standing of Charles, and whether the monarch is protected by the law or is above the law," he explained.
"And the answer to that was no - they told me that we don't see any reason why he is. And secondly, Camilla and her family are certainly not above the law. So that argument's already been had and settled."
The engineer alleged that the King and Queen consort Camilla began their close relationship in 1965, a year before when his birth certificate says he was born.
He claimed his research suggests the royals first became close in 1965 after they met at Winston Churchill's funeral.
However, Charles and Camilla are widely reported to have met at a polo match in Windsor Great Park in 1970.
Dorante-Day further claimed that nine months before he was born, Charles was sent on an Australian trip and Camilla was absent from the British social scene.
He maintained that Camilla kept him hidden for eight months, with the help of the royal family.
He further claimed that it was a condition of the adoption that his names 'Simon' and 'Charles' remain unchanged.
Dorante-Day further said the inconsistencies on his birth certificate and his name prove that he is of royal blood.
After the Queen's passing, Dorante-Day shared a tribute saying he was as affected by her death, as everyone else.
"Since finding out about the loss of my grandmother aka Lilibet, I've been inundated with messages of condolence for the loss. Thank you all for your kind words, thoughts, and concern," he said.
He added, "Rest in peace Aka, you are in God's hands now, I know in me I will always carry a piece of you".
He further said the Queen's death marked the loss of him "pleasantly" being able to get to the bottom of his biological heritage since she never responded to his letter.
"As many of you have expressed my family and I are mourning not just the loss of Her Majesty but the loss of another opportunity to resolve this issue pleasantly, the right way."
"So, despite the lost opportunity of getting to personally hear her version of events, and the great sadness we all feel at her passing, on a personal and public scale it will be business as usual."
