George Papadopoulos, the former Trump campaign adviser who triggered the Russia investigation, will make his first appearance before congressional investigators Thursday.

Special counsel Robert Mueller charged Papadopoulos with lying to the FBI about his contacts with Russian intermediaries. He was sentenced in September to two weeks in prison. Papadopoulos will speak behind closed doors to two GOP-led House committees that are investigating partisan bias at the Justice Department.

Since he was sentenced to two weeks in prison, Papadopoulos has been eager to talk publicly. He has spent many nights on Twitter, along with his wife, venting anger with the FBI and implying that he was set up in the investigation. He has said on Twitter that he would like to talk to Congress about his "suspicious encounters" with an Australian diplomat and a professor who were links to his case. And his lawyer sent a letter to the committees this week in which he listed nine people he wants to discuss in the interview, including both of those men.

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"As you know, in the spirit of full transparency, Mr. Papadopoulos had requested that his interview be public," wrote Caroline Polisi in an Oct. 22 letter obtained by The Associated Press. "We understand that is not an option at this time, but would welcome the opportunity to do so at a later date."

Papadopoulos, who served as a foreign policy adviser to Trump's campaign, has been a central figure in the Russia investigation dating back before Mueller's May 2017 appointment. He was the first to plead guilty in Mueller's probe and the first Trump campaign adviser to be sentenced. His case was also the first to detail a member of the Trump campaign having knowledge of Russian efforts to interfere in the 2016 presidential election while it was ongoing.

According to a sweeping indictment, Russian intelligence had stolen emails from Hillary Clinton's campaign and other Democratic groups by April 2016, the same month Papadopoulos was told by the professor, Joseph Mifsud, that Russian officials had told him they had "dirt" on Clinton in the form of "thousands of emails." According to a New York Times report last year, Papadopoulos then told the Australian diplomat, Alexander Downer, who tipped off the FBI.

It's unclear how many lawmakers will attend the interview, since Congress is in recess.

Papadopoulos has also said he wants to talk to the Senate intelligence committee, which is investigating Russian interference in the 2016 election. A House intelligence committee investigation wrapped up earlier this year, with Republicans saying that there was no evidence of collusion between Russia and President Donald Trump's campaign.