Meghan Markle’s estranged half-sister Samantha Markle has reportedly been placed on a police watch list.

Samantha, 53 — who was turned away by security when she attempted to drop off a letter to the Duchess of Sussex at Kensington Palace earlier this year — has been put on Scotland Yard’s “fixated persons list” because of the “reputational risk” she poses to the royal family, according to U.K. outlet The Sunday Times.

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According to Scotland Yard’s website, the Fixated Threat Assessment Centre helps “assess and manage the risks from lone individuals who harass, stalk or threaten public figures.”

“You can’t protect someone like the Duchess of Sussex without knowing the background of her family. But someone like Samantha presents a risk rather than a threat. She is not committing criminal offenses, but she is causing concerns for the royal family,” a Scotland Yard source reportedly told the outlet.

“Samantha could make a scene and create headlines with her actions — and let’s face it, she’s kind of already done that,” the insider added.

Although Scotland Yard has declined to comment on the report, Samantha has denied it, telling the Sunday Times, “I would only say that is ludicrous. I’m not a reputational risk.”

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Samantha — the daughter of Meghan’s father, Thomas Markle, from his first marriage — has been outspoken since Meghan first stepped onto the royal stage. Neither Samantha nor Thomas, 74, attended Meghan’s wedding in May.

In addition to telling the press that she was writing a memoir titled The Diary of Princess Pushy’s Sister, Samantha later took responsibility for arranging Thomas’ staged paparazzi photos in the weeks leading up to the royal wedding — about which Thomas admitted he lied to Harry.

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Samantha went on to confess that she had been “cashing in” on Meghan’s fame.

“Let’s face it — we all have to survive. Money makes the world go round, so if you want to call that cashing in, that’s fine, but I think no one in media would refuse a paycheck for talking about the royal and, as a family, we’re not subject to royal protocol,” she told Good Morning Britain in July.

Image zoom Samantha Markle ITV

Addressing Meghan and Samantha’s relationship, a source close to the former Suits star previously told PEOPLE that “Meghan has no relationship with her half-siblings, nor has she ever had one.”

“They were out of the house by the time she was born,” added the insider.

Since the wedding, Samantha has amped up her public criticism of Meghan, who is currently expecting her first child with Harry.