WASHINGTON — Federal prosecutors in Washington are investigating a years-old leak of classified information about a Russian intelligence document, and they appear to be focusing on whether the former F.B.I. director James B. Comey illegally provided details to reporters, according to people familiar with the inquiry.

James Comey wearing a suit and tie: James B. Comey, the former F.B.I. director, has been a frequent target of President Trump.© Monica Jorge for The New York Times James B. Comey, the former F.B.I. director, has been a frequent target of President Trump.

The case is the second time the Justice Department has investigated leaks potentially involving Mr. Comey, a frequent target of President Trump, who has repeatedly called him a “leaker.” Mr. Trump recently suggested without evidence that Mr. Comey should be prosecuted for “unlawful conduct” and spend years in prison.

The timing of the investigation could raise questions about whether it was motivated at least in part by politics. Prosecutors and F.B.I. agents typically investigate leaks of classified information around the time they appear in the news media, not years later. And the inquiry is the latest politically sensitive matter undertaken by the United States attorney’s office in Washington, which is also conducting an investigation of Mr. Comey’s former deputy, Andrew G. McCabe, that has been plagued by problems.


Law enforcement officials are scrutinizing at least two news articles about the F.B.I. and Mr. Comey, published in The New York Times and The Washington Post in 2017, that mentioned the Russian government document, according to the people familiar with the investigation. Hackers working for Dutch intelligence officials obtained the document and provided it to the F.B.I., and both its existence and the collection of it were highly classified secrets, the people said.

The document played a key role in Mr. Comey’s decision to sideline the Justice Department and announce in July 2016 that the F.B.I. would not recommend that Hillary Clinton face charges in her use of a private email server to conduct government business while secretary of state.

The investigation into the leaks began in recent months, the people said, but it is not clear whether prosecutors have impaneled a grand jury or how many witnesses they have interviewed. What prompted the inquiry is also unclear, but the Russian document was mentioned in a book published last fall, “Deep State: Trump, the F.B.I., and the Rule of Law” by James B. Stewart, a Times reporter.

A lawyer for Mr. Comey declined to comment, as did a spokeswoman for the United States attorney’s office in Washington.

Mr. Trump has repeatedly pressured the Justice Department to investigate his perceived enemies. In 2018, he told the White House counsel at the time, Donald F. McGahn II, to prosecute Mrs. Clinton and Mr. Comey. Mr. McGahn refused, telling the president that he did not have the authority to order investigations and that doing so could prompt abuse-of-power accusations. Mr. Trump had also discussed the appointment of a second special counsel to conduct the investigations he sought.

Previously, federal prosecutors in New York scrutinized Mr. Comey after his personal lawyer and friend, Daniel C. Richman, provided the contents of a memo about Mr. Comey’s interactions with Mr. Trump to a Times reporter at Mr. Comey’s request. Though officials retroactively determined that the memo contained classified information, prosecutors declined to charge Mr. Comey with illegally disclosing the material. The Justice Department’s inspector general, who had examined Mr. Comey’s conduct and referred his findings to prosecutors in New York, concluded that Mr. Comey violated F.B.I. policy.

a group of people standing next to a man in a suit and tie: The former F.B.I. deputy director Andrew G. McCabe, center, was accused of misleading investigators conducting an administrative review.© Stephen Crowley/The New York Times The former F.B.I. deputy director Andrew G. McCabe, center, was accused of misleading investigators conducting an administrative review.

The latest investigation involves material that Dutch intelligence operatives siphoned off Russian computers and provided to the United States government. The information included a Russian analysis of what appeared to be an email exchange during the 2016 presidential campaign between Representative Debbie Wasserman Schultz, Democrat of Florida who was also the chairwoman of the Democratic National Committee at the time, and Leonard Benardo, an official with the Open Society Foundations, a democracy-promoting organization whose founder, George Soros, has long been a target of the far right.

In the email, Ms. Wasserman Schultz suggested that then-Attorney General Loretta E. Lynch would make sure that Mrs. Clinton would not be prosecuted in the email case. Both Ms. Wasserman Schultz and Mr. Benardo have denied being in contact, suggesting the document was meant to be Russian disinformation.

Debbie Wasserman Schultz standing next to a fence: Representative Deborah Wasserman Schultz has said she never communicated with Leonard Benardo, an official with the Open Society Foundations, suggesting that a document that describes an email exchange between them was meant to be Russian disinformation.© Erin Schaff/The New York Times Representative Deborah Wasserman Schultz has said she never communicated with Leonard Benardo, an official with the Open Society Foundations, suggesting that a document that describes an email exchange between them was meant to be Russian disinformation.

That document was one of the key factors that drove Mr. Comey to hold a news conference in July 2016 announcing that investigators would recommend no charges against Mrs. Clinton. Typically, senior Justice Department officials would decide how to proceed in such a high-profile case, but Mr. Comey was concerned that if Ms. Lynch played a central role in deciding whether to charge Mrs. Clinton, Russia could leak the email.

Whether the document was fake remains an open question. But American officials at the time did not believe that Ms. Lynch would hinder the Clinton email investigation, and neither Ms. Wasserman Schultz nor Mr. Benardo had any inside information about it. Still, if the Russians had released the information after the inquiry was closed, it could have tainted the outcome, hurt public confidence in the Justice Department and sowed discord.

Prosecutors are also looking at whether Mr. Richman might have played a role in providing the information to reporters about the Russia document and how it figured into Mr. Comey’s rationale about the news conference, according to the people familiar with the investigation. Mr. Comey hired Mr. Richman at one point to consult for the F.B.I. about encryption and other complex legal issues, and investigators have expressed interest in how he operated.

Mr. Richman was quoted in the April 2017 article in The Times that revealed the document’s existence. A month later, The Post named Ms. Wasserman Schultz and Mr. Benardo as subjects of the document in a detailed article. A lawyer for Mr. Richman declined to comment.

Typically, prosecutors would decline to open investigations into older leaks of classified information because the passage of time makes such cases much harder to pursue as the memories of witnesses fade. Also, the initial leaks can generate more leaks as more officials feel comfortable discussing the information with journalists because it has become public.

Multiple news stories about the classified disclosures also make it harder to determine whether one person was speaking to reporters or several people, according to former law enforcement officials. And the larger the universe of government officials who have been briefed on classified information, the more difficult it is to find the leaker, former officials said. In this case, lawmakers were briefed on the Russian document in addition to executive branch officials.

In inquiries where investigators determine that a leak is coming from members of Congress or their staff, political sensitivities make those cases difficult to investigate. Most of the time, former officials said, such inquiries are dead on arrival.

Additionally, investigators could also decline to open an investigation into an older leak because it might further harm national security if the information once again made headlines, as in this inquiry.

“Leak cases are incredibly difficult to prosecute,” said Brian J. Fleming, a former lawyer with the Justice Department who worked on many such cases in his work on national security issues. “They are very challenging to present to a jury both as an evidentiary matter and in terms of presenting a compelling, coherent narrative. That is a big reason so few leak cases get charged and even fewer ever go to trial.”

Still, if a government agency is determined to hunt down the source of a leak, as the C.I.A. was in the case of Jeffrey A. Sterling, a former C.I.A. officer who was convicted of leaking details about an anti-Iran operation to a Times reporter, Justice Department officials generally will pursue the case aggressively.

Justice Department officials might also be interested in making an example of Mr. Comey, a development almost certain to please Mr. Trump. Like the Obama administration, the Trump Justice Department has regularly prosecuted officialswho providedsensitive information to reporters.

Federal prosecutors in the District of Columbia have embraced politically fraught cases under the United States attorney, Jessie K. Liu, an ambitious prosecutor who has angled for bigger jobs in the Trump administration.

She aggressively pushed for the prosecution of Mr. McCabe on suspicion of lying to investigators about sensitive law enforcement information provided to a reporter. Mr. McCabe was accused of misleading investigators conducting an administrative review, not a criminal inquiry; typically, such cases are not referred for prosecution.

The relatively straightforward case against Mr. McCabe has dragged on for more than 20 months. Prosecutors have refused to tell Mr. McCabe’s lawyers whether they intend to bring charges.

Ms. Liu’s office also charged Gregory B. Craig, a onetime White House counsel in the Obama administration, after prosecutors in New York passed on the case. Mr. Craig was charged with lying to the F.B.I. about his work for the Ukrainian government, but a jury last year quickly acquitted him, handing Ms. Liu an embarrassing defeat.

Mr. Trump nominated Ms. Liu last month to be the Treasury Department’s under secretary for terrorism and financial crimes. He had previously tapped her to be the No. 3 spot in the Justice Department, but she withdrew from consideration after Senator Mike Lee, Republican of Utah, raised concerns about her conservative credentials.