WASHINGTON (WFLA) — A senior staffer for U.S. Rep. Matt Gaetz of Florida resigned on Friday amid an investigation into whether or not the Republican congressman broke federal sex trafficking laws, according to NBC News.

The report from NBC News said Luke Ball resigned on Friday. Ball had served as Gaetz’ communications director.

According to the New York Times, Ball did not release any kind of public statement explaining why he was leaving. The former communications director had worked with Gaetz since 2017 when the Florida Republican first started serving in the U.S. House of Representatives, the report said.

The Times first reported about the Department of Justice investigation into Gaetz on Tuesday. The federal investigation started over accusations that the congressman had a sexual relationship with a 17-year-old girl and paid her to travel with him, the Associated Press reported.

The AP, citing two people familiar with the matter, reported Friday that federal prosecutors are examining whether or not Rep. Gaetz and political ally Joel Greenberg may have paid underage girls or offered them gifts in exchange for sex. Greenberg is a former Florida tax collector.

Gaetz has denied all accusations against him and said Tuesday that he and his family have been “victims of an organized criminal extortion involving a former DOJ official seeking $25 million while threatening to smear my name.”

The congressman added that his family has been cooperating with the FBI.