Jeff Bezos’ personal security team has launched an investigation into how his text messages ended up in The National Enquirer, and the inquiry is increasingly convinced that political motives are behind the disclosure.

The investigation is taking place independent of Amazon, and Bezos, the world’s richest man, is personally funding it. Investigators want to know who leaked the texts that publicly blew up Bezos’ marriage earlier this month by revealing, in lurid detail, his affair with Los Angeles news anchor Lauren Sanchez.

The leaked text messages contained flowery missives from Bezos such as “I want to smell you, I want to breathe you in. I want to hold you tight,” and “I love you, alive girl. I will show you with my body, and my lips and my eyes, very soon.”

According to three people familiar with the probe, investigators initially explored the possibility that Bezos’ phone was hacked. But those sources say a digital forensic analysis turned up no evidence of a hack and the theory was quickly discounted.

They also looked into Sanchez herself, and whether she might have leaked the messages in an effort to break up Bezos’ marriage. But all three sources said the inquiry has not uncovered evidence that she was involved.

A third theory, that the leak was politically motivated, is one that investigators believe would explain not just the leak itself, but its publication in the Enquirer, rather than a more reputable outlet, and the extensive resources that the tabloid devoted to digging into the story.

That avenue of investigation stems from Bezos’ new role as a punching bag for President Donald Trump. The president gleefully promoted the Enquirer’s story, using it to hammer Bezos over his ownership of The Washington Post, which Trump frequently maligns as a hostile advocacy arm of Amazon.

With Bezos’ sudden political lightning rod status in mind, investigators are eyeing individuals with ties to various figures in the president’s orbit, who might have also had access to Bezos’ or Sanchez’s phones.

Jon Hammond, a spokesman for Enquirer parent company American Media Inc., declined to comment on the publication’s sourcing. An Amazon spokesman did not respond to multiple requests for comment.

The investigation into the leak has not concluded, and the team behind it has yet to issue any formal statement about it.

The fact that the texts ended up at the Enquirer has fueled Bezos’ investigators’ suspicions that the leak was politically motivated. The tabloid’s chief executive, David Pecker, admitted last month to using the Enquirer to facilitate a hush money payment to one of Trump’s alleged mistresses during the final weeks of the 2016 campaign. Pecker is a longtime Trump friend and ally, and the tone of his publication’s coverage—it labeled Bezos a “schmuck” in one story, for example—has struck investigators as even more venomous than typical Enquirer fare.

The scandal and federal investigations during the Trump era have, however, tested the durability of the Pecker-Trump relationship. As The Daily Beast reported in August, not long after the feds raided the office of Michael Cohen, President Trump’s former attorney and fixer, Pecker and top Enquirer brass made a concerted effort to distance themselves publicly from the president, and abruptly halted their previously routine, glowing coverage of Trump.

On Tuesday, in an apparent attempt to preempt The Daily Beast’s reporting on this story, Roger Stone, a longtime Trump advisor facing criminal charges related to the investigation into Russian meddling in the 2016 election, claimed to the conspiracy site InfoWars that The Daily Beast was working on an article alleging that he had conspired with the Trump administration to hack Bezos’ text messages and feed them to the Enquirer.

Stone also said that that story had been pitched by “the Amazon PR people.”

All of those claims are false.