Author Daniel Halper told "The Daily Briefing" Thursday that the arrest of Ghislaine Maxwell is the biggest story related to the Jeffrey Epstein case since the convicted pedophile's jailhouse suicide last year.

“She’s the primary character, aside from Jeffrey Epstein," said Halper, the co-author of "A Convenient Death: The Mysterious Demise of Jeffrey Epstein."

"She [Maxwell] was with him from his rise in New York. [She] helped him really get a social footing, social standing in New York City and make big acquaintances that paid off."

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Halper noted that Maxwell's circle of friends included the likes of Prince Andrew and Bill Clinton.

“There are lots of pictures of her with President Trump, so she had a very big social circle," he added. "Part of that was by virtue of who her father was. He [Robert Maxwell] was a publishing magnate in London who died mysteriously himself in the early ’90s [1991]."

Maxwell was arrested Thursday morning in Bradford, N.H., the FBI confirmed to Fox News. She was ordered held without bail by a New Hampshire federal judge following an intial court appearance by video link.

The 58-year-old faces charges of conspiracy to entice minors to travel to engage in illegal sex acts, enticement of a minor to to travel to engage in illegal sex acts, conspiracy to transport minors with intent to engage in criminal sexual activity, transportation of a minor with intent to engage in criminal sexual activity, and two counts of perjury.

Maxwell has been accused in civil court filings of facilitating a sex-trafficking operation that brought girls -- some as young as 14 -- to Epstein's Manhattan home, though until Thursday she had not been formally charged with any criminal wrongdoing.

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Halper told host Dana Perino that no reporters had been able to track Maxwell down and she had successfully sought to be out of the media spotlight before her arrest.

“The New York Post had a picture of her shortly after Epstein’s death ... There are some wild reports about her being in France or being elsewhere around the world or being in yachts," he said. "It turns out she was just in New Hampshire, kind of laid low. She had this LLC that she purchased through cash to help hide her identity.”