President Donald Trump's relationship with his daughter and senior adviser, Ivanka, frequently crosses the line of "appropriate father/daughter behavior," ousted White House aide Omarosa Manigault Newman claims in her new book, Unhinged, out Tuesday
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President Donald Trump‘s relationship with his daughter and senior adviser, Ivanka, frequently crosses the line of “appropriate father/daughter behavior,” in the opinion of ousted White House aide Omarosa Manigault Newman, as recounted in her new book, Unhinged, out Tuesday.

“As long as I’d known Trump, I’d observed the way he hugs, touches, and kisses Ivanka; the way she calls him Daddy,” Manigault Newman writes. “In my opinion, based on my observations, their relationship goes right up to the line of appropriate father/daughter behavior and jumps right over it. I believe he covets his daughter. It’s uncomfortable to watch them.”

The former Apprentice contestant, who was fired from her position as director of communications for the White House Office of Public Liaison in December 2017, adds that in Trump’s Apprentice days, “It appeared to me that Ivanka had gotten so used to his touching her in ways that made others cringe and either didn’t notice it anymore or purposefully allowed it to happen.”

The White House did not immediately respond to PEOPLE’s request for comment.

The president has attacked Manigault Newman on Twitter over other claims she’s made in her tell-all book, including that the president is in “mental decline” and that he can be heard using the “N-word” on an alleged tape recording from before his presidency. (The alleged recording has not been publicly released, but Manigault Newman says she has heard it.)

White House Press Secretary Sarah Huckabee Sanders also issued a statement saying that the book “is riddled with lies and false accusations,” adding that “it’s sad that a disgruntled former White House employee is trying to profit off these false attacks, and even worse that the media would now give her a platform, after not taking her seriously when she had only positive things to say about the President during her time in the administration.”

Trump has raised eyebrows in the past over sexually charged comments he’s made about his daughter. He famously joked during a 2006 appearance on The View, “If Ivanka weren’t my daughter, perhaps I’d be dating her.” And in a 2003 interview with Howard Stern, Trump said his daughter has “the best body.” In another interview, Trump gave the radio host the okay to call Ivanka a “piece of ass.”

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In Unhinged, Manigault Newman describes other alleged incidents where Trump boasted about his daughter’s body and encouraged others to speak about her in sexual terms.

She claims that during filming of his reality show The Apprentice in 2007, Trump “egged on” contestant and Kiss bassist Gene Simmons after he “leered at” Ivanka’s breasts and called her “sexy.” A rep for Simmons did not immediately respond to PEOPLE’s request for comment.

Manigault Newman says Trump asked Simmons in a room full of other contestants: “What do you think of Ivanka? How’s she doing?”

“She’s a very, very sexy, desirable young woman who I’m looking forward to getting to know much better if you know what I mean, with all due respect,” Simmons replied, according to Manigault Newman.

She adds that the other contestants were taken aback by “Donald’s obvious delight” in hearing his daughter being described in such a manner.

Years later, during a meeting amid Trump’s presidential campaign, Manigault Newman claims the then-candidate “insisted” that the attendees stop everything and admire his daughter in a tight-fitting skirt.

“Ivanka came into the room wearing a fitted skirt. The entire meeting had to stop so (Trump) could gush about her body,” Manigault Newman alleges ” ‘You look great! I like the way that skirt fits. Doesn’t Ivanka look great?’ He insisted we all agree that his daughter’s tight skirt was very flattering. I thought, ‘Why don’t the two of you just cut it out?’ ” (Because Manigault Newman did not identify any of the other attendees, her account could not be independently confirmed.)

But Manigault Newman claims that Trump’s alleged inappropriate interest in his daughter is beneficial for Ivanka as well.

“I believe she exploits his fixation with her to get her way,” Manigault Newman writes, although she provided no examples of Ivanka doing so.