By Katelyn Polantz and Marshall Cohen, CNN

(CNN) -- Two former business associates of former national security adviser Michael Flynn were charged with trying to influence American politicians to seek the extradition of a Turkish cleric, according to an indictment filed in the Eastern District of Virginia.

Bijan Rafiekian, also known as Bijan Kian, and a Dutch-Turkish businessman Kamil Alptekin, who also uses the first name Ekim, were charged with conspiracy and acting as an agent of a foreign government. Alptekin was also charged with making four false statements in a May 2017 FBI interview.

The charges come amid a sweep of prosecutions of individuals illegally lobbying for foreign governments -- previously a rarely charged crime -- and amid special counsel Robert Mueller's inquiry into influence in the 2016 presidential campaign.

Kian made an appearance in federal court in Virginia Monday morning. He was released on bail.

The 66-year-old Californian, whom authorities say worked closely with Flynn on the lobbying effort throughout 2016, will appear in court again Tuesday. There is still a warrant out for the arrest of Alptekin, who lives in Istanbul.

The two men were indicted by a federal grand jury last week.

Their alleged plot, the Justice Department said in a news release, involved using a company founded by Kian and Flynn to "delegitimize the Turkish citizen in the eyes of the American public and United States politicians" to pave the way for his extradition. US authorities allege that high-level members of Turkey's government approved financing for the gambit and Alptekin kept them updated on its progress.

US authorities said the goal of the lobbying project was to press for the extradition of the Turkish cleric Fethullah Gulen, who has lived in self-imposed exile in Pennsylvania since 1999. The Turkish government and President Recep Tayyip Erdogan blames Gulen for a failed attempted coup against him in 2016, which Gulen has denied, and has been aggressively pushing for the US government to extradite him.

President Donald Trump said last month that he is not considering extraditing Gulen.

Kian's attorney did not immediately respond to a request for comment Monday. Last year, amid news reports that his work was under federal investigation, Alptekin defended himself on Twitter and denied the allegations.

"I never lobbied or contracted lobbyist on behalf of the Turkish Government," he tweeted in March 2017. He repeated the claims for many months, tweeting in December 2017: "The Turkish Government did NOT provide supervision or direction to the work I commissioned" from Flynn's company.

Flynn was charged by Mueller for lying to investigators last year, including about his work at the Flynn Intel Group Inc. on behalf of Turkey. A federal judge in Washington, DC, will sentence Flynn on Tuesday.

The former national security adviser is not charged in the Virginia case against his colleagues because federal prosecutors have said Flynn gave "substantial assistance" by cooperating with Mueller and on other investigations, likely including the Kian and Alptekin case.

Throughout the Turkish lobbying case made public Monday, Flynn is referred to as "Person A." The indictment describes Kian discussing with Flynn meeting with Turkish leaders and accepting payments through Flynn's company throughout 2016 for the lobbying work. They worked on the lobbying project as late as October 2016, a month before Trump won the election and Flynn helped with the presidential transition.

This story is breaking and will be updated.