Authorities announced charges Monday against two men involved in a Turkish lobbying campaign that was headed by President Donald Trump’s former National Security Adviser Michael Flynn.

An indictment unsealed Monday showed authorities charged Flynn’s former business partner, Bijan Kian, 66, and Turkish businessman Kamil Ekim Alptekin, 41, with conspiracy, acting in the U.S. as illegal agents of the government of Turkey and making false statements to the FBI.

Justice Department officials said in a news release that Kian and Alptekin were accused of conspiring to “covertly influence U.S. politicians and public opinion” for the Turkish government.

Kian, whose full name is Bijan Rafiekian, made an initial appearance Monday in federal court in Alexandria, Virginia, The Washington Post reported. Alptekin remained at large Monday.

Kian ran a lobbying firm, identified by The Associated Press as the Flynn Intel Group, with Flynn and conspired with Alptekin to sway public opinion against Turkish cleric Fethullah Gulen, according to court records and the Post. Turkish President Recep Tayyip Erdogan blamed followers of Gulen, who has lived in the U.S. since 1999, for an attempted military coup in 2016.

Authorities accused Kian and Alptekin of illegally lobbying to discredit Gulen and have him extradited. According to the indictment, Alptekin worked at the direction of the Turkish government, but the defendants worked to conceal that fact.

The charges, which were filed under seal last week, appear to shed light on the cooperation of Flynn, who last year admitted to lying about several aspects of the lobbying work. He pleaded guilty in 2017 to lying to investigators with special counsel Robert Mueller’s team and agreed to cooperate with investigators.

Prosecutors said in a pre-sentencing memo filed last week that Flynn has provided information in three separate investigations, including an undisclosed criminal investigation and the probe into Russian election meddling and its possible ties to Trump and his campaign officials.

Flynn will be sentenced Tuesday in the case.

The Associated Press contributed to this report.