As President Donald Trump moves to purge his administration of perceived disloyalty, one of his top deputies is also doggedly working to expose perhaps the most famous dissident in its ranks.

Officially, assistant to the president Peter Navarro is Trump's point-man on trade policy. But Navarro has also taken it upon himself in recent weeks to uncover the identity of the person known simply as “Anonymous,” the senior Trump administration official who has railed against the president in the New York Times opinion pages and, most recently, in a bestselling book titled A Warning, and whose actual identity has so far confounded White House leak hunters.

Since at least the time of the impeachment process against Trump, Navarro—whom the president affectionately calls “my Peter”—began conducting his own private investigation into the identity of Anonymous, according to three sources with knowledge of Navarro’s efforts.

One of those sources described Navarro’s investigative efforts as partially an in-depth analysis of the language and phrases used in Anonymous’ book and other public writings. The process, as described to The Daily Beast, mimics forensic linguistic profiling, and the goal is to cross-reference Navarro's “profile” with a list of potential suspects.

Two other people familiar with Navarro’s efforts said he had zeroed in on at least one likely suspect and that he has compiled his findings in a written report that he’s shared with White House Counsel Pat Cipollone, who is leading official internal efforts to unearth Anonymous’ identity.

One of the sources who spoke with The Daily Beast specifically asked to be identified in this story as a “senior administration official” because that is how Anonymous is self-described in the famous op-ed and book. Navarro declined to comment when reached by The Daily Beast on Sunday.

A White House spokesman did not provide comment by press time. But Navarro, it should be noted, is not working alone. Instead, his efforts are part of a multi-pronged effort inside the administration to figure out who, exactly, Anonymous is. In addition to work by the counsel’s office and Navarro, a handful of staffers on the National Security Council have taken it upon themselves to conduct their own unofficial probe, one source said.

Despite those efforts, Anonymous has vexed and fascinated political and media figures since writing a New York Times column in September 2018 describing himself or herself as “part of the resistance inside the Trump administration.” In November 2019, the person released A Warning, which lambasted Trump for his alleged erratic, reckless, and ignorant behavior and actions in office. The book claimed that numerous other administration officials share Anonymous’ disdain for the president, and frequently work to subvert his agenda.

Trump himself has taken notice, and on many occasions has privately asked senior aides about efforts to unmask Anonymous, according to those close to the president. Both he and his allies have taken Anonymous’ presence as confirmation of the existence of a “deep state” cabal operating within the federal government to thwart the president’s efforts to disrupt the status quo in Washington.

That view has inspired the West Wing’s efforts this month to purge the White House of perceived subversives, such as Lt. Col. Alexander Vindman, who testified to Congress about Trump’s phone call with the Ukrainian president. Vindman is not suspected of being Anonymous, but was removed from his NSC post last week in retaliation for his (legally mandatory) testimony before a House panel investigating conduct that led to the president’s impeachment.

It’s not clear whether Anonymous actually remains in an administration post, or has moved on. Reporting since his or her Times column has floated a variety of potential culprits. Every administration official who’s been asked has denied being Anonymous. But then that’s what Anonymous said he or she would do.

“For now,” the person wrote in A Warning, “if asked, I will strenuously deny I am the author of this book, including when the president demands we each disavow it.”