An associate of Rep. Matt Gaetz's is working toward a plea deal with federal prosecutors investigating a sex trafficking operation, potentially escalating the legal and political jeopardy facing the Florida congressman.

The revelation that a political ally of Gaetz's, Joel Greenberg, is seeking to strike a plea deal with investigators came during a hearing Thursday at federal court in Orlando. It's a significant step in the case and signals that Greenberg could potentially serve as a witness in the Justice Department’s investigation into Gaetz.

“I am sure Matt Gaetz is not feeling very comfortable today,” Fritz Scheller, a lawyer for Greenberg, said after the hearing.

FILE — In this Sept. 30, 2019, file photo, Seminole County Tax Collector Joel Greenberg talks to the Orlando Sentinel during an interview at his office in Lake Mary, Fla. Greenberg has been charged with trafficking a minor, stalking a political opponent, producing fake IDs, identity theft, embezzlement and bribery. But it's his friendship with U.S. Rep. Matt Gaetz that is attracting the most attention now as federal investigators have launched a sex trafficking probe into the Republican congressman from the Florida Panhandle. (Joe BurbankOrlando Sentinel via AP, File)

FILE — In this Sept. 30, 2019, file photo, Seminole County Tax Collector Joel Greenberg talks to the Orlando Sentinel during an interview at his office in Lake Mary, Fla. Greenberg has been charged with trafficking a minor, stalking a political opponent, producing fake IDs, identity theft, embezzlement and bribery. But it's his friendship with U.S. Rep. Matt Gaetz that is attracting the most attention now as federal investigators have launched a sex trafficking probe into the Republican congressman from the Florida Panhandle. (Joe BurbankOrlando Sentinel via AP, File)

Federal prosecutors are examining whether Gaetz and Greenberg paid underage girls or offered them gifts in exchange for sex, according to two people familiar with the matter who spoke on condition of anonymity because they could not discuss details publicly. Gaetz has denied the allegations and insists he will not resign his seat in Congress.

A call to the congressman's cellphone on Thursday yielded a message that he was not accepting calls at this time.