Vanessa and Tiffany Trump Were ‘Inappropriately Close’ with Secret Service Agents, New Book Claims

Astrid Stawiarz/Getty; Alec Tabak - Pool/Getty Tiffany Trump (left) and Vanessa Trump

Tiffany and Vanessa Trump had eyebrow-raising relationships with the Secret Service agents protecting their family while Donald Trump was in the White House, a new book claims.

The upcoming Zero Fail: The Rise and Fall of the Secret Service, by Pulitzer Prize-winning Washington Post reporter Carol Leonnig, describes how former President Trump's youngest daughter and Donald Trump Jr.'s now-ex-wife both became "inappropriately — and perhaps dangerously — close" to members of the security detail. (A spokeswoman for Tiffany denies this.)

The Guardian and The Washington Post obtained advanced copies of Leonnig's book, which is scheduled to be published on May 18.

According to The Guardian's description, Leonnig cites Secret Service agents to report that Vanessa had "started dating one of the agents who had been assigned to her family."

It's not clear when this began. However, Vanessa filed for divorce from Don Jr., both 43, in March 2018, and Leonnig writes that the agent did not face professional repercussions over the relationship as Vanessa was not then a protectee of the agency.

Sources at the time told PEOPLE that the couple had weathered reports of his affair with a Celebrity Apprentice contestant years earlier but that, while their union recovered as they subsequently had more children, the relationship was in trouble long before the split.

"Even before all this Trump presidency stuff started, they weren't good and their marriage was strained," one source told PEOPLE in March 2018, describing Don Jr. and Vanessa as living "separate lives."

According to Leonnig's book, Tiffany sparked her own connection with a Secret Service agent with whom she "began spending an unusual amount of time alone" after a breakup.

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Andrew H. Walker/Getty From left: Vanessa Trump and Donald Trump Jr.

Agency officials "became concerned at how close Tiffany appeared to be getting to the tall, dark and handsome agent," Leonnig writes, according to The Guardian and the Post.

The agent was reassigned, though both he and Tiffany said there was no inappropriate relationship. It is unclear when this episode unfolded during the Trump presidency.

Asked for comment about Leonnig's book and her reporting on Tiffany and Vanessa, a Secret Service spokesperson said: "The U.S. Secret Service is aware of an upcoming book which re-hashes past challenges the agency overcame and evolved from. Now and throughout its 156 year history, the agency's skilled workforce is dedicated to the successful execution of its critical protective and investigative missions."

A spokeswoman for Tiffany told the Post her "experience with the Secret Service was entirely professional" and that claims otherwise were "nothing more than gossip." (Tiffany and Vanessa did not respond to calls and texts from PEOPLE.)

Tiffany has been dating Michael Boulos since 2019. The couple announced their engagement the day before President Trump left office in January.

"Got engaged to the love of my life! Looking forward to our next chapter together," Boulos, the son of a wealthy family with businesses in Nigeria, wrote on Instagram at the time.

He and Tiffany first met at Lindsay Lohan's club in Mykonos in 2018, according to a source. Speaking with PEOPLE in January 2019, however, Lohan downplayed any matchmaking role.

Lohan said then that she was only recently introduced to Boulos through mutual friends and described her relationship with Tiffany as "friendly."

Chip Somodevilla/Getty Tiffany Trump

Tiffany Trump/Instagram From left: Michael Boulos and Tiffany Trump at the White House

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Leonnig's book's touts itself as "the first definitive account of the rise and fall of the Secret Service, from the Kennedy assassination to the alarming mismanagement of the Obama and Trump years, right up to the insurrection at the Capitol on January 6."

Leonnig is the co-author of another Trump book, A Very Stable Genius, and was part of the Post team that won a Pulitzer Prize for reporting on Edward Snowden's leaks from the National Security Agency.

According to The Guardian, Leonnig writes it wasn't clear if President Trump knew about the allegations of unusual relationships between agents and his daughter and daughter-in-law.

Leonnig also writes that Trump had complained about some Secret Service agents being too overweight for the job, although he may have been confusing office staff with his government security.

"I want these fat guys off my detail," Trump allegedly said, according to Leonnig's new book. "How are they going to protect me and my family if they can't run down the street?"

Just before leaving office in January, Trump took the unusual step of extending Secret Service protection for his adult children for six months, including Don Jr., Tiffany, and their siblings Eric Trump and Ivanka Trump.

Former presidents and first ladies receive lifetime security, but Secret Service agents aren't typically assigned to former first family members who are adults.

A Secret Service source told PEOPLE in January that Trump issued the last-minute, six-month extension as a "transition period" for his adult children.

President Joe Biden would need to approve a further extension after that, the Secret Service source said then.

Other than Eric, Trump's kids have all made plans to relocate to Florida since he lost the 2020 election.