The controversial uncle of the Princess of Wales has joined a British reality television show, igniting major concerns within the royal family and Kensington Palace.

Millionaire Gary Goldsmith, 58, the younger brother of Kate Middleton’s mother, Carole, entered ITV’s Celebrity Big Brother UK house on March 5 with other “famous” faces including X-Factor celebrities Sharon Osbourne, Louis Walsh and Love Island winner Ekin-Su Cülcüloğlu.

The inclusion of the “heavily-tattooed” Goldsmith, who has been married four times and appeared in court on domestic violence charges, comes as Kate has been seen in public for the first time since Christmas Day after planned abdominal surgery.

The show’s premise requires its celebrity contestants, referred to as housemates, to perform weekly tasks and live in isolation from the outside world in a custom-built “house” under video surveillance.

To avoid getting evicted, the more controversial the celebrity is, the more likely their fellow celebs will allow them to stay on.

By all accounts, Goldsmith is seen as a firm favourite to stay, in the hope he might spill secrets about the royals.

“Gary said he’s been read the riot act by Kate’s mum Carole and her dad Michael,” a source told London’s Sun newspaper.

“They aren’t happy he’s going into Celebrity Big Brother.

“It is infuriating for them. Kate doesn’t need this stress.”

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‘Bad  boy’

In Goldsmith’s promotional video for the controversial show, he describes Kate, 42, as “simply perfect … very normal”, and how he’s the uncle of the future queen of England.

Then he speaks with loose lips.

“I often read that people think I’m a bit of a bad boy … winding people up is probably my favourite hobby … every part of me is just riddled with mischief and danger,” he says.

According to his ITV biography, Goldsmith worked as an IT operator after school, then joined IT recruitment firm Computer Futures.

He sold his shares for a reported £17 million ($33 million) in 2005 and bought a villa in Ibiza, named Maison de Bang Bang, where he still lives (and where Prince William and Kate reportedly visited a year later).

In 2017, he was arrested for assaulting his wife, Julie-Ann, after a drunken argument in which she accused him of taking drugs. He pleaded guilty and was handed a £5000 ($9000) fine and ordered into alcohol rehabilitation.

Grounds for concern? You bet.

Gary Goldsmith at Westminster Magistrates’ Court, London, in 2017. Photo: AAP

The first episode

Goldsmith has already lived up to expectations, saying Kate could be watching the show from “behind a sofa”.

He also spoke about the Sussexes, who quit the royal family in 2020 and moved to California.

He said Prince Harry and Meghan Markle could not “throw your family under a bus in such a dramatic style” – referring to “books” written by the couple – and still be expected “to be invited round for Christmas”, reported Sky News.

“I have the opinion that Harry was really, really, really loved, massively loved, when they were a threesome – Kate, William and Harry.

“Then suddenly there’s an extra dynamic that comes in, puts a stick in the spokes and creates so much drama that I don’t generally think is there, and re-wrote the history and said how unhappy he was, and I just don’t think that’s fair.”

“It is pretty sad because … at some point [Harry is] going to want to come back and be part of the gang – he might need to. But I think we’re a very forgiving nature and … everybody will give him a chance again,” added Goldsmith.

Gary Goldsmith and daughter Tallulah, now 19, at Pippa Middleton’s wedding in 2017. Photo: Getty

No longer ‘eye-to-eye’

A Sun insider said that “in the eyes of the public, Gary’s become the black sheep of the Middleton family. Carole is his sister, so there will always be love, but they no longer see eye-to-eye on lots of things”.

“He has said he doesn’t have their blessing to go into the house but is going full-steam ahead anyway.

Goldsmith’s current relationship with the Prince and Princess of Wales is unclear.

Good Morning Britain’s tabloid television panel didn’t hold back, with Andrew Piece groaning Goldsmith was “a narcissistic self-publicist”.

“We’ve all got embarrassing relatives,” said Kevin Maguire.