Beata Zawrzel/Zuma

Federal agents on Monday raided the Los Angeles-area home of an FBI whistleblower who has alleged that bureau higher-ups thwarted an investigation of Rudy Giuliani, two sources said. The whistleblower, FBI agent Jonathan Buma, has said that Giuliani “may have been compromised” by Russian intelligence while working as a lawyer for Donald Trump.

Scott Horton, an attorney representing Buma, said that Horton was presented with a search warrant when he went into the bureau’s Orange County, California, field office on Monday. Agents searched Buma’s person, after which a large group of agents searched his residence, confiscating all the digital media in Buma’s home, including the computers and watches of his wife and four children.

A search warrant reviewed by Mother Jones said the agents were looking for classified documents they suspected Buma had removed without authorization.

Horton said that the search turned up no classified material and that the agents seized only Buma’s own whistleblower complaint, which is not classified. The raid “is designed to be in retaliation for the whistleblower complaints,” Horton claimed. “It’s very heavy harassment.”

Buma has filed statements with congressional investigators outlining his findings related to Giuliani and detailing his allegations that senior bureau officials shut down his investigative efforts and later retaliated against him. Buma’s claims, some of which leaked this summer, received substantial media attention, including from Mother Jones, in part because he has countered GOP arguments that the bureau was eager to investigate Trump allies but reluctant to look into Hunter Biden. Buma—who has said his work first turned up some of Hunter Biden’s Ukrainian dealings—claims the opposite was true. He asserted in a statement filed with the Senate Judiciary Committee that FBI agents moved quickly to scrutinize information on Biden’s business activities, even as his own investigation into Giuliani was shut down without explanation.

Recent news reports have revealed that billionaire tech investor Peter Thiel and Charles Johnson—a onetime Thiel associate and prominent former far-right agitator—had previously acted as confidential informants for Buma.

The FBI has previously declined to comment on Buma’s allegations. A spokesperson for the FBI’s Los Angeles field office did not respond to an inquiry Tuesday.