An ex-girlfriend of Representative Matt Gaetz was expected to testify Wednesday before a federal grand jury in Orlando, two sources familiar with the matter confirmed to CBS News.

Gaetz has been under investigation to determine if he violated sex trafficking laws and obstructed justice in that probe. Gaetz has previously denied all wrongdoing, and said he has never paid for sex, nor had sex with an underage girl.  

The ex-girlfriend, who CBS News is not naming to protect her privacy, has been negotiating an immunity deal with federal prosecutors  and could be a potential key witness in both the sex-trafficking investigation and the obstruction of justice probe, two sources told CBS News. 

CBS News has confirmed the woman and her attorney had left the courthouse on Wednesday afternoon.  

Tim Jansen, a lawyer for the ex-girlfriend, declined to comment. The Department of Justice declined to comment.

Isabelle Kirshner, an attorney for Gaetz, told CBS News in a statement that “we have seen no credible basis for a charge against Congressman Gaetz. We remain steadfast in our commitment to challenge any allegations with the facts and law.”

News of the ex-girlfriend’s expected testimony was first reported by CNN.

One of the sources said that as part of the obstruction probe, investigators are looking into whether Gaetz had a phone call with two women, one of whom was already a witness in the federal investigation. The other woman on the call was the ex-girlfriend, the source said.

The obstruction inquiry and alleged phone call were first reported by Politico.

Multiple sources say both the witness and the ex-girlfriend traveled with Gaetz to the Bahamas in September 2018. Investigators are trying to determine if the women were illegally trafficked across state or international state lines for the purposes of sex with the Congressman. 

A third woman was also on the trip who was 18 years old at that time, but according to sources, she was introduced to Gaetz when she was 17. Federal investigators are looking into whether Gaetz had a sexual relationship with her when she was 17.

CBS News is not naming the 17-year-old because she is an alleged victim of a sex crime. 

Two sources familiar with the matter told CBS News it was Joel Greenberg, a former Florida county tax collector and associate of Gaetz’s, who introduced Gaetz to that woman when she was 17 years old. Greenberg pleaded guilty in May 2021 to six federal charges, including trafficking of a minor.