The father of nine claims that his adoptive grandmother, who worked for the Queen, was involved in arranging his adoption, positioning him as a hidden member of the Royal family.

Man who claims to be King Charles’s secret lovechild sparks Royal Family red alert (Image: Getty)

An Australian man who claims to be King Charles and Queen Camilla’s secret love child has put the Royal security services on a high alert this weekend, it has been reported.

Simon Charles Dorante-Day, 58, a British-born man, is convinced that he is the illegitimate son of King Charles III and Queen Camilla, given up for adoption shortly after birth and raised by Royal household staff, reports MailOnline.

For years, he has been calling for a DNA test to prove his claim. However, he has now been placed on a security watch list following concerns that he might take matters into his own hands.

With the King and Queen’s upcoming tour announced, Mr Dorante-Day hinted at plans to confront the Royal couple upon their arrival in Sydney on Friday night.

Mr Dorante-Day said in May: “What am I going to do this time? Well, I’d be a very silly person not to take action when he comes into the same jurisdiction as me. But I think I’d be even sillier to reveal my hand prematurely.”

King Charles III And Queen Camilla Visit Australia And Samoa (Image: Getty)

Close protection experts have now confirmed that the Australian will be closely monitored by Royal bodyguards during the King and Queen’s visit to the country.

A protection expert requesting anonymity told Daily Mail Australia: “There is probably around 20 names on that watchlist already. And certainly anyone making a noise publicly will be of high interest.

“Background searches will have already been carried out on any names they have and it’s standard to do psych evaluations based on any criminal convictions and social media.”

Mr Dorante-Day was adopted at around eight months old in August 1966 in Portsmouth, on England’s south coast, at a time when Camilla was 18 and Charles was 17.

The father of nine claims that his adoptive grandmother, who worked for the Queen, was involved in arranging his adoption, positioning him as a hidden member of the Royal family.

He is now seeking to reveal the truth and claim his place as the rightful heir to the throne, replacing William as the Prince of Wales.

However, Royal security teams have reportedly briefed police and ASIO to ensure he stays away from Charles and Camilla during their visit to Australia.

The Royal couple is scheduled to arrive in Sydney on Friday night, spend the weekend there, then travel to Canberra on Monday before returning to Sydney ahead of their departure on Wednesday.

The Royal protection squad will be responsible for ensuring Mr. Dorante-Day is kept at a distance throughout the trip.

“Police have the authority to issue a move on notice to anyone they see fit,” said the minder with 30 years experience of protecting star and high-profile dignitaries.

The expert added: “The psychological brief would have determined if that was necessary already.

“They take everything into account including the grudge the person may have with them and will also be watching for agitated behaviour.”