Australian local Simon Charles Dorante-Day believes he bares a striking resemblance to the King of England

A 58-year-old man living in Australia who is adamant he is related to the Royal Family believes that there’s one tell-tale sign that proves he’s correct.

For those unfamiliar with Simon Charles Dorante-Day, he has gone viral on several occasions within the last decade, after claiming he is the love child of King Charles and Queen Camilla.

Apparently, there’s actually some pretty sound reasoning behind Simon’s theory, the first being the dates around his birth.

Simon was born back in 1966 to parents living in England, who subsequently made the decision to put him up for adoption.

Thankfully, however, he was adopted by a loving duo who took him over to Australia to raise him.

It wasn’t until recently, however, that one of his adoptive grandparents – who was said to have been a former household employee of the late Queen Elizabeth – lifted the lid of his apparent Royal heritage.

According to Simon, when his grandmother was on her deathbed, she disclosed that he was closely related to the Charles and Camilla.

The Royal couple would have been around 17-years-old when Simon was born.

Apparently, it isn’t just his grandmother’s claims that have swayed the Aussie to the understanding that he has some very well-to-do family members.

In fact, he believes that the silence the British institution have kept on the matter ever since he came forward with his claims tells him all he needs to know.

Speaking with 7NEWS.com.au, Simon noted: “It’s worth me pointing out that Charles and Camilla, Buckingham Palace, the entire royal family – not one of them has ever said my claims are not true.

“They’ve never denied what I believe, told me I’m wrong. And I think their silence speaks volumes.”

One of the biggest issues with Simon’s claims, however, is that – according to official records – his supposed ‘parents’ Charles and Camilla didn’t meet until five years after he was born.

The duo both went on to marry others – Camilla to Andrew Parker-Bowles and Charles to the late Princess Diana – but famously continued their romance behind the scenes, though they never welcomed any children together.

Despite this, Simon remains convinced that he bears some resemblance to the Royal pair, who rekindled their public relationship in the early 2000s before tying the knot in 2005.

So much so, that he even has a Facebook account wholly set up to prove his heritage, upon which he shares regular updates with his supporters and photos.

Taking to social media recently, he went as far as to share a photo of his own granddaughter, whom he claims bears a striking resemblance to Princess Charlotte, the daughter of Charles’ son, Prince William, and Kate Middleton.

In the snap, Simon’s granddaughter can be seen bearing similarly long brown hair, as the duo pose respectively for official-looking photos.

“Very very much alike,” a follower of his penned in the comments, before another added: “Very similar, both beautiful girls”.