Bijan Kian, board member of the U.S. Export-Import Bank and Michael Flynn, former National Security Advisor.

Bijan Kian, 66, and Kamil Alptekin were charged in U.S. District Court in Eastern Virginia with acting as unregistered agents of the Turkish government, according to court documents made public Monday.

That conspiracy allegedly included a scathing op-ed article that Flynn wrote about the cleric, Fethullah Gulen, which was published on Election Day 2016.

A former business partner of President Donald Trump 's first national security advisor, Michael Flynn, and another man have been indicted on conspiracy charges related to efforts to smear and win the extradition of an exiled Turkish cleric at the behest of the government of Turkey.

Alptekin, a 41-year-old Turkish national who currently is in Turkey, also was charged with four counts of making false statements to the FBI, according to the indictment, issued by a grand jury last Wednesday.

Kian, an Iranian-American who is a resident of San Juan Capistrano, California, appeared Monday morning in court in Alexandria, Virginia, and was released without bail. Kian served on Trump's transition team, in the division related to the Office of the Director of National Intelligence.

From 2006 through 2011 he was a board member of the Export-Import Bank of the United States.

The indictment offers new details about Flynn's work advancing the interests of the Turkish government, even as he remained one of the most outspoken and politically polarizing boosters of Trump's presidential campaign.

Click here to read the indictment

The two men are accused by federal authorities of attempting to "covertly and unlawfully" influence U.S. politics and public opinion in favor of extraditing Gulen, who was blamed by Turkey's president, Recep Erdogan, for an attempted coup in 2016. Cabinet-level officials in Turkey approved the budget for the project, according to prosecutors.

"The defendants sought to discredit and delegitimize the Turkish citizen in the eyes of politicians," the court filing said.

Flynn's firm, which had been hired by Alptekin's Netherlands-based company, was part of that alleged effort.

Gulen, who lives in Pennsylvania, has denied that he was behind the efforts to overthrow the Turkish government. On Sunday, Turkish Foreign Minister Mevlut Cavusoglu claimed that the U.S. was "working on" extraditing Gulen to Turkey, The New York Times reported. Cavusoglu said that Trump made the comment to Erdogan during the recent G-20 summit in Argentina.

The release of the indictment comes a day before Flynn, a 60-year-old retired lieutenant general, is due to be sentenced in federal court in Washington for making false statements to FBI agents.

Flynn has been cooperating with special counsel Robert Mueller's ongoing investigations.

A spokesman for the special counsel's office referred CNBC's questions to federal prosecutors in Virginia.

Flynn last year pleaded guilty to lying about his conversations in late 2016 with the then-Russian Ambassador to the U.S. Sergey Kislyak.

But Mueller's team also noted in a sentencing memo earlier this month that Flynn also made false statements to the Justice Department related to work his company did "for the principal benefit of the Republic of Turkey" soon after the 2016 coup attempt.