George Nader, who was a key witness in special counsel Robert Mueller's Russia investigation, was arrested on child pornography charges Monday in New York, federal prosecutors announced Monday.
Nader was arrested upon arrival at John F. Kennedy International Airport for "transporting visual depictions of minors engaged in sexually explicit conduct."
He previously pleaded guilty to the same charge in 1991, the Justice Department said.
If convicted, he faces a minimum sentence of 15 years in prison and a maximum of 40 years.
Nader will make an initial appearance in court in New York but was charged by prosecutors in Virginia.
The Mueller report mentions Nader in nearly four dozen footnotes, including references to his interviews with special counsel investigators, and other materials, like his emails and text messages.
Prosecutors filed a secret criminal complaint against Nader on January 17, 2018, according to the Justice Department. CNN previously reported that Nader was questioned by the FBI on that date, the first of several sessions with investigators from Mueller's office.
Nader helped the Mueller investigation by providing multiple interviews and testifying before the grand jury. The Mueller report said "all but one" of his interviews were conducted "under a proffer agreement" where he could provide information with some legal protection.
He is cited extensively in the portions of the report about the Seychelles meeting in between Trump supporter Erik Prince and a Russian banker with close ties to Russian President Vladimir Putin. His testimony about his role in the secret January 2017 liaison undercut Prince's claims that the meeting was a random encounter and that it was not coordinated with anyone from the Trump transition.
This story is breaking and will be updated.