▶ Watch Video: Gaetz associate expected to plead guilty in federal case

Joel Greenberg, a former county tax collector and associate of Congressman Matt Gaetz, has signed a plea agreement with the federal government that includes a clause stipulating he’ll “cooperate fully with the United States in the investigation and prosecution of other persons,” according to federal court records filed in Florida. 

In the plea agreement made public Friday, Greenberg signed his initials, agreeing to enter a guilty plea on the charges of sex trafficking with a child, production of a false identification, aggravated identify theft, wire fraud, stalking and conspiracy to commit an offense against the United States. 

According to the plea agreement, “One of the individuals who Greenberg paid for commercial sex acts was a minor under the age of 18 for part of the time when Greenberg paid her to engage in commercial sex acts with him and others.” The document also says Greenberg “introduced the minor to other adult men, who engaged in commercial sex acts with the minor in the Middle District of Florida,” although the plea agreement does not identify the other adult men. 

The U.S. District Court for the Middle District of Florida in Orlando has scheduled a change-of-plea hearing for Monday. Greenberg pleaded not guilty last month to charges related to embezzlement and sex trafficking of a child. 

As a part of the plea agreement, the defendant, “agrees to cooperate fully with the United States in the investigation and prosecution of other persons, and to testify, subject to a prosecution for perjury or making a false statement, fully and truthfully before any federal court proceeding or federal grand jury in connection with the charges in this case and other matters…”

Greenberg’s attorney, Fritz Scheller, had already said Greenberg was expected to strike a deal by May 15.

CBS News has confirmed the investigation into Greenberg is what sparked an ongoing investigation into Gaetz. Federal investigators are looking into whether Gaetz had a sexual relationship with a 17-year-old. Gaetz insists he is innocent. His name is not mentioned in Greenberg’s plea agreement, and Gaetz is not charged with any crimes. 

“Congressman Gaetz doesn’t seem to be named nor referenced in Mr. Greenberg’s plea. Congressman Gaetz has never had sex with a minor and has never paid for sex,” a spokesperson for Gaetz said, reiterating that the congressman is “innocent.” 

— CBS News’ Michael Kaplan contributed to this report