Nathan Nelson, a former director of military affairs for Rep. Matt Gaetz, R-Fla., pushed back against the FBI after he said two agents questioned him as part of an ongoing investigation of the congressman.

Nelson told reporters during a Monday news conference that when agents went to his house to question him, they made it seem that they believed Nelson resigned because he was aware of Gaetz’s involvement in illegal activity. Nelson said that was false, and his departure from Gaetz’s office had been planned in advance.

ORGY, UNDERAGE GIRLS, SEX GAMES AND EXTORTION: INSIDE THE ALLEGATIONS SURROUNDING REP. MATT GAETZ

"This baseless claim against me leaves me further convinced that the allegations against Congressman Gaetz are likewise fabricated and merely an attempt to discredit a very vocal conservative," Nelson said in a news conference organized by Gaetz's office.

Nelson, who said he remains "loosely affiliated" with Gaetz's office as an unpaid adviser, stated that he notified Gaetz’s office that he had spoken to FBI agents, but that he has not spoken to the congressman personally in months.

A federal sex trafficking probe involving Gaetz and a then-17-year-old girl was reported by the New York Times last week. The Times cited three anonymous sources "briefed on the matter," which alleges that the 38-year-old had a relationship with the girl and paid for her travel at one point.

In response to the report, Gaetz denied the allegations in an interview with Fox News’ Tucker Carlson. He went on to say that he is the target of an extortion plot involving an ex-Justice Department official seeking a $25 million payoff.

MATT GAETZ SAYS HE WON’T RESIGN AS PRESSURE MOUNTS

According to documents obtained and reported by the Washington Examiner, the alleged scheme revolves around attempts by former Air Force intelligence officer Bob Kent and Beggs & Lane attorney David McGee, a former federal prosecutor, to free ex-FBI agent Robert Levinson, who disappeared in Iran.

According to the Examiner report, the documents contained a promise to help Gaetz with legal woes related to a supposed federal probe involving him and underage prostitutes, in exchange for the money. 

Gaetz is denying allegations that he paid women for sexual favors or was involved with any underage girls. Meanwhile, the Associated Press has reported that several Republican lawmakers and aides believe Gaetz’s future in Congress may be in jeopardy as his popularity wanes.

Rep. David Valadao, R-Calif., said he was transferring 2020 campaign donations from Gaetz to an organization supporting domestic abuse survivors. Former Rep. Barbara Comstock, R-Va., pushed for Gaetz’s removal from Congress after the Justice Department’s investigation became public knowledge.

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Despite the pressure, Gaetz told the Wall Street Journal on Friday that he will not resign.

"Of course not," he said.

Fox News' Marisa Schultz, Morgan Phillips and Mike Emanuel contributed to this report.