A U.S. federal grand jury is investigating potential disclosures of classified information in the book former national security adviser John Bolton published in June over strong objections from the Trump administration, a source familiar with the situation said Tuesday.

The development signals that Bolton may face much more severe legal trouble than just the pending lawsuit that seeks to strip him of the proceeds from “The Room Where It Happened,” the tell-all account that generated a slew of brutal press for President Donald Trump.

The judge assigned to that suit rejected the Justice Department’s bid to block publication of the book, but said Bolton appeared to have deliberately violated nondisclosure agreements he signed and could face criminal jeopardy.

Spokespeople for the Justice Department, Bolton and his publisher, Simon & Schuster, declined to comment on the development.

“We are aware of reports that grand jury subpoenas have been issued seeking information concerning the publication of Ambassador Bolton’s recent book,” Bolton’s lawyer, Chuck Cooper, said. “Ambassador Bolton emphatically rejects any claim that he acted improperly, let alone criminally, in connection with the publication of his book, and he will cooperate fully, as he has throughout, with any official inquiry into his conduct.”

In his ruling denying an injunction against the book, U.S. District Court Judge Royce Lamberth opined that such a move would be ineffective because advance copies had already been distributed to and reported on by media outlets. But the appointee of President Ronald Reagan excoriated Bolton for his book.

“Defendant Bolton has gambled with the national security of the United States. He has exposed his country to harm and himself to civil and potentially criminal liability,” Lamberth wrote in his order.

Trump jumped on the ruling, issuing Twitter messages amplifying the judge’s claim that Bolton may have run afoul of criminal statutes against unauthorized disclosure of classified national security secrets. “Bolton broke the law and has been called out and rebuked for so doing, with a really big price to pay,” the president wrote.

(SD-Agencies)