(CNN) A longtime US Senate staffer was arrested late Thursday on charges of lying to federal agents as part of an investigation related to the unauthorized disclosure of non-public information, according to a federal indictment.

Federal prosecutors accuse James Wolfe, the former security director for the Senate Intelligence Committee, of lying to FBI agents in December 2017 about his contacts with three reporters, including through his use of encrypted messaging applications. According to the indictment, Wolfe made false statements to the FBI about providing two reporters with non-public information related to the matters occurring before the committee.

The indictment provides a detailed account of Wolfe's interactions with one specific unnamed reporter. Prosecutors say Wolfe eventually admitted to being in a personal relationship with that reporter, dating back to 2014.

Yet he "maintained that he had never disclosed to REPORTER #2 classified information or information that he learned as Director of Security for the (Committee) that was not otherwise publicly available."

Investigators obtained email and phone records for the pair allegedly showing "tens of thousands of electronic communications," including a text message from Wolfe that read in part: "I've watched your career take off even before you ever had a career in journalism. . . . I always tried to give you as much information that I could and to do the right thing with it so you could get that scoop before anyone else . . . ."

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