Chelsea Manning has been subpoenaed to testify before a grand jury in the investigation of Julian Assange, officials said, one of several indicators that prosecutors remain interested in WikiLeaks’ publication of diplomatic cables and military war logs in 2010.

Prosecutors in Virginia have been pursuing a case based on conduct that predates WikiLeaks’ publication of hacked emails during the 2016 presidential campaign, and it’s not clear investigators are interested in that activity. Officials discussed the investigation of Assange, who founded WikiLeaks, on the condition of anonymity because of the secrecy of the grand jury process.

Manning, whose subpoena was first reported by the New York Times, is a former Army private who served seven years in a military prison for passing secret State Department cables and military documents to WikiLeaks before rece iving a commutation from President Barack Obama.

Manning’s attorneys have filed a motion to quash the subpoena.

“I object strenuously to this subpoena, and to the grand jury process in general,” Manning said in a statement. “We’ve seen this power abused countless times to target political speech. I have nothing to contribute to this case and I resent being forced to endanger myself by participating in this predatory practice.”

The subpoena was signed last month by Gordon Kromberg, a national security prosecutor on the Assange case. Kromberg last month persuaded a judge to leave sealed an indictment against Assange despite its inadvertent exposure in an unrelated court filing last year.

Under Obama, Justice Department officials had decided not to pursue charges against Assange and WikiLeaks after concluding that to do so could set a precedent that paved the way for prosecuting news organizations for publishing classified information. But the case got a fresh look under President Trump.

Steve Vladeck, a professor at the University of Texas at Austin School of Law, said the Justice Department likely indicted Assange last year to stay within the 10-year statute of limitations on unlawful possession or publication of national defense information, and is now working to add charges. “There’s nothing else that would make sense,” he said.

“The heart of the controversy is, there’s never been a successful prosecution” for publishing classified information, Vladeck said. “There has always been the specter of a First Amendment defense.”

Peter Zeidenberg, a national security defense attorney, said he cannot see grounds for Manning to refuse the subpoena. “She’s already been prosecuted, she’s been convicted, she served a sentence,” he said. “She has no Fifth Amendment privilege over self-incrimination. If she doesn’t testify then she’ll be held in contempt.”

Manning appears to be the latest individual subpoenaed to testify before the grand jury investigating Assange in the Eastern District of Virginia.

Last July, computer expert David House, who befriended Manning in 2010 at a hacker space in Boston he founded, testified for 90 minutes before the grand jury. In an interview, House said he met the WikiLeaks founder in January 2011 while Assange was under house arrest at Ellingham Hall, a manor house 120 miles northeast of London. Assange was fighting an extradition request by Sweden, where he faced an inquiry into allegations of sexual assault.

Assange asked House to help run political operations for WikiLeaks in the United States. “Specifically, he wanted me to help achieve favorable press for Chelsea Manning,” he said.

House, who testified in exchange for immunity, said the grand jury was interested in his relationship with Assange. “They wanted full insight into WikiLeaks, what its goals were and why I was associated with it,” he said. “They wanted explanations of why certain things occurred and how they occurred. . . . It was all related to disclosures around the war logs.”

The grand jury seemed interested in whether Assange had solicited Manning to hack on WikiLeaks’ behalf, but did not press “very hard” on that, he said.

During her trial, Manning testified that she acted on her own to send documents to WikiLeaks and no one associated with WikiLeaks pressured her into giving more information.

House was not asked about WikiLeaks’ 2016 release of Democratic emails, which U.S. intelligence agencies have assessed were hacked by Russians. Nor did he have personal knowledge of that, he said.

He was never told what charges prosecutors were contemplating.

House said his last contact with Assange was in 2013 and his last contact with WikiLeaks was in 2015.

House said he fears retribution for being associated with WikiLeaks and Manning in 2010 and does not believe the U.S. prosecution is warranted.

“This is not an investigation borne out of a concern for national security,” he said. “It is an investigation borne out of retribution and revenge against Mr. Assange over the [2010] leak that he precipitated, and how this leak impacted the careers of politicians in Washington, D.C.”

Daniel Domscheit-Berg, a onetime WikiLeaks spokesman who has grown estranged from Assange, said in an interview he was contacted by the German federal police in October 2017 and told that U.S. authorities wished to talk to him “about the Manning-Julian connection.” He also received a March 2018 letter repeating the request from then-U. S. attorney in the Eastern District, Dana Boente.

He said the German police told him the FBI was interested in “what possible contact — possible coordination’’ occurred between Assange and Manning, he said. The Americans appeared to be interested in “possible solicitation” by Assange of Manning, he said.

Domscheit-Berg told the German police he was not interested in speaking to the FBI.