Washington — California Gov. Gavin Newsom said Monday that he and his wife are under investigation by the Justice Department.

In a video posted to X, Newsom said federal agents have sought to speak to his family, friends and former employees, demanded records and dug through years of documents. He accused the Justice Department under President Trump of “abusing the grand jury process.”

“Donald Trump isn’t just coming after me because of my mean tweets,” Newsom said. “He’s coming after me because I’m considering running for president, because he hates that I consistently called him out over and over again for his lies and deceit. Donald Trump is simply the most corrupt president in American history.”

Newsom cited other perceived political enemies of Mr. Trump, including New York Attorney General Letitia James, former FBI Director James Comey and former Federal Reserve Chairman Jerome Powell, who have been investigated by the Justice Department. The governor said he has joined the president’s “hit list.”

“After calling for my arrest last year, Donald Trump directed his Department of Justice to investigate me, and just in the last week I’ve learned that his campaign has reached my own home. To get me, he’s coming after my wife,” the California governor said.

It’s unclear what Newsom and his wife, Jennifer Siebel Newsom, are under investigation for, and the governor did not provide details about what information or documents investigators have sought. Siebel Newsom, who calls herself the first partner of California, is a documentary filmmaker. She founded The Representation Project, a nonprofit organization, and co-founded California Partner’s Project, a nonprofit that promotes gender equality.

A source familiar with the investigations said there are several ongoing Justice Department probes related to the governor that are being handled by the U.S. Attorney’s Office in Sacramento. At least one of the investigations has been going on for about a year, the source said, and one or more originated with a whistleblower complaint.

An adviser to the governor said federal agents have contacted individuals and organizations connected to Newsom and his wife, issued subpoenas for records and conducted interviews involving groups tied to the governor and first partner. The adviser said investigators expanded their probe as Acting Attorney General Todd Blanche took the helm of the Justice Department.

The president nominated Blanche, who was Mr. Trump’s defense attorney, for attorney general last week.

“To Donald Trump, who I know is watching, because he watches everything, I have a message for you,” Newsom said. “You can subpoena my records, you can investigate me, you can harass me, put my name on every and any enemies list you have, but leave my wife and family out of your personal vendetta.”

Newsom is a frequent and vocal critic of Mr. Trump’s, and in his social media video, the governor accused the president of corruption and seeking to profit off the presidency.

Mr. Trump, in turn, often attacks the California governor, calling him “dumb” and referring to him by the derogatory nickname “Newscum.” The president told reporters last year that Newsom should be arrested, and said “his primary crime is running for governor because he’s done such a bad job.”

An investigation into Newsom would be the latest by the Justice Department targeting public officials who have opposed the president.

The former interim U.S. attorney in eastern Virginia sought and secured indictments against James and Comey last year, but a judge dismissed the charges after finding the prosecutor, Lindsey Halligan, was unlawfully appointed. Comey was indicted a second time in North Carolina over a now-deleted photo he shared to Instagram last year that depicted seashells arranged to say “86 47.” He has denied wrongdoing.

Federal prosecutors also investigated Powell, then the Fed chairman, and renovations of the central bank’s Washington, D.C., headquarters earlier this year. Mr. Trump had often lambasted Powell over interest rate decisions, and suggested that the renovation project could be grounds to fire him. But the probe was dropped in April after a key senator vowed to block the confirmation of Mr. Trump’s pick to succeed Powell as Fed chair as long as the investigation remained active.