Two former associates of ex-national security adviser Michael Flynn have been charged with "covertly and unlawfully" trying to influence American politicians in a plot to extradite a Turkish cleric living in the U.S.

Bijan Kian, 66, and Kamil Ekim Alptekin, 41, were charged Monday with conspiracy to act as agents of a foreign government.

Bijan Kian speaks during the Kazakhstan Investment Forum in New York in 2009. Daniel Acker / Bloomberg via Getty Images file

Kian, a California-based former business partner of Flynn, was released without bond after an appearance in a federal court in Virginia. His lawyer, Robert Trout, declined to comment. Alptekin, a Dutch-Turkish businessman who has so far evaded authorities, is also charged with three counts of lying to federal agents.

Federal prosecutors said the scheme involved a secret effort to build support among American politicians to remove from the U.S. the cleric Fethullah Gulen, a longtime target of Turkish President Recep Tayyip Erdogan living in self-imposed exile in Pennsylvania.

"The defendants sought to discredit and delegitimize the Turkish citizen in the eyes of politicians and the public, and ultimately to secure the Turkish citizen's extradition," according to an indictment.

Flynn does not appear in the indictment by name but is referred to as "Person A" and described as having a key role in the plot that prosecutors say was orchestrated by the Turkish government.

The charges were brought less than two weeks after Flynn was described in court papers as having provided substantial assistance in several investigations. Flynn, in pleading guilty to lying to federal investigators last year, also admitted to making false statements about his foreign lobbying work.

The indictment refers to an op-ed that Flynn wrote for The Hill newspaper on Election Day that compared Gulen to former Iranian leader Ayatollah Khomeini. The reference parroted language used in a draft prepared by Kian, the indictment says.

"We all remember another quiet, bearded elder cleric who sat under an apple tree ... in the suburbs of Paris in 1978," Flynn wrote in the op-ed blaming Gulen for directing a failed coup against Erdogan and urging the U.S. government to stop providing him refuge. "He claimed to be a man of God who wanted to be a dictator."

According to the indictment, the defendants used Flynn's firm, the now-dissolved Flynn Intel Group where Kian was a partner, to damage Gulen's reputation and kept secret that the work was directed by the Turkish government.

The indictment says the effort was put in motion in late July 2016 after the Justice Department denied a request by Turkey to arrest and extradite Gulen.

Kian emailed Alptekin on July 27, 2016, saying that he had a "detailed discussion" with Flynn the previous night, the court papers say.

"We are ready to engage on what needs to be done," Kian wrote, the indictment says.

In his reply, Alptekin said he had met with a Turkish government minister. "He is interested in exploring this seriously and it is likely he'll want to meet with you and (Flynn)," Alptekin wrote, according to the indictment.

He added: "Needless [sic] to tell you but he asked me not to read in anyone else for the time being and keep this confidential."

Working with Flynn, they gave the operation a name,"Truth Campaign," later changed to "Project Confidence," prosecutors said. The scheme included using a Dutch company owned by Alptekin, Inovo, to appear to be the "client" of Flynn's firm and pay the fee of $600,000 in three installments, according to the indictment.

On a weekly basis, Kian and Flynn held calls with Alptekin to update him on the progress of the project, the court papers say. "Alptekin relayed this information to Turkish officials and informed (Kian) and (Flynn) whether the Turkish officials were satisfied with the work (Flynn's firm) was performing," the indictment says.

NBC News reported in November 2017 that federal investigators were zeroing in on Kian for his role in the Flynn Intel Group's failure to disclose its work on behalf of foreign governments.

Flynn pleaded guilty in December 2017 to a charge of lying to the FBI about his conversations with Russian ambassador Sergey Kislyak in the weeks before President Donald Trump took office. He has been cooperating with investigators.

The charges against Kian and Alptekin, which were brought by prosecutors with the Eastern District of Virginia, came the day before Flynn is due to be sentenced in federal court. Special Counsel Robert Mueller's team has argued that he should receive a light sentence in exchange for his cooperation.