April 9 (UPI) -- Rep. Adam Kinzinger, R-Ill., became the first GOP congressman to call for the resignation of Rep. Matt Gaetz, R-Fla., amid reports of a federal investigation into whether Gaetz violated federal sex trafficking laws.

Kinzinger tweeted Thursday night: "Matt Gaetz needs to resign." In his tweet, Kinzinger linked to an article about the Justice Department's investigation into Gaetz.

Gaetz, who has not been charged, has denied any wrongdoing since The New York Times first reported last month on the federal investigation. Gaetz has said he is "absolutely not resigning."

The New York Times reported investigators are examining whether Gaetz violated sex trafficking laws by engaging in a sexual relationship with a 17-year-old and paying for her to travel with him.

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