Joshua Schulte, a former CIA employee, has been charged with leaking classified information, the Justice Department announced on Monday.
A grand jury indicted Schulte on a series of charges, including illegal gathering of national defense information and illegal transmission of unlawfully possessed national defense information.
According to the indictment, Schulte, 29, obtained classified information in 2016 related to US intelligence-gathering capabilities and then provided that information to an organization that "purports to publicly disseminate classified, sensitive, and confidential information."
The organization is not named in the charging document and is referred to only as "Organization-1." A number of media outlets, including The New York Times and Politico, identified the organization as WikiLeaks on Monday.
A Justice Department prosecutor revealed in a January court session in New York that a former CIA employee had been suspected of leaking classified documents to WikiLeaks, which posted thousands of pages of CIA documents with secret cyber tools in March 2017.
A court transcript from a January federal hearing in New York related to child pornography charges brought against Schulte reveals that he was a "target" of the leak investigation. The Washington Post first reported the government's characterization of Schulte in May, after obtaining a transcript of the proceedings.
In a statement on Monday, Manhattan US Attorney Geoffrey Berman said Schulte "allegedly used his access" at the CIA "to transmit classified material to an outside organization," adding that "during the course of this investigation, federal agents also discovered alleged child pornography in Schulte's New York City residence."
"Unlawful disclosure of classified intelligence can pose a grave threat to our national security, potentially endangering the safety of Americans," Berman said.
Schulte was also charged in the indictment on counts of theft of government property, making false statements, obstruction of justice, and receipt and possession of child pornography.
WikiLeaks and an attorney who has represented Schulte did not immediately return a request for comment on the indictment, but The New York Times has previously reported that Schulte's family maintains he did not do anything wrong.