Washington CNN  — 

Federal investigators scrutinizing Rep. Matt Gaetz are seeking the cooperation of a former Capitol Hill intern who was once a girlfriend of the Florida Republican, sources familiar with the matter tell CNN.

Investigators could also soon gain the formal cooperation of a second key witness, former Florida county tax collector Joel Greenberg, who is approaching a deadline this week to strike a plea agreement with the government on more than two dozen charges he’s facing.

The pursuit of the cooperation comes as investigators are nearly finished collecting evidence, one source said. The probe, which is examining whether Gaetz broke federal sex trafficking, prostitution and public corruption laws and whether he had sex with a minor, has been ongoing for months.

But decisions on whether to charge Gaetz have yet to be made and will fall to prosecutors in the public integrity section of the Justice Department. That decision is likely to take some time, another source familiar with the matter said, as the Justice Department considers whether there’s sufficient evidence for an indictment.

The cooperation of Greenberg and the former girlfriend could be among the final steps in the probe of Gaetz. Investigators view both as crucial to understanding the relevance of hundreds of transactions they have obtained records of, including those involving payments for sex, sources familiar with the investigation tell CNN. The ex-girlfriend could also be questioned by investigators about a second woman as they try to determine whether Gaetz may have slept with that woman when she was only 17.

The former girlfriend, who did not work in Gaetz’s office on Capitol Hill, is of interest to investigators because she was on a trip Gaetz took to the Bahamas in 2018 and is believed to have knowledge of drug use and arrangements with women, the sources say.

Gaetz has been isolated politically but has remained defiant in the six weeks since the investigation first became public, launching a nationwide speaking tour alongside the controversy-generating Georgia Republican, Rep. Marjorie Taylor Greene, with the investigation swirling around him.

Gaetz has denied any wrongdoing, including paying for sex or having sex with a minor.

In response to CNN’s questions for this story, a Gaetz spokesperson said: “Your ‘story’ is simply a regurgitation of the same falsehoods you’ve been peddling for two months now without a shred of evidence or a single on-record accuser.”

Timothy Jansen, a lawyer for the ex-girlfriend, declined to comment.

The FBI and Justice Department also declined to comment.

An intern and former Gaetz girlfriend

The former girlfriend was one of the women who traveled with Gaetz to the Bahamas in 2018, said one source with knowledge of the matter.

The Bahamas trip has become a focus of investigators, who are scrutinizing whether women were paid to travel for sex with Gaetz and others, and whether the trip was part of an effort to illegally influence Gaetz in the area of medical marijuana, CNN has previously reported. Gaetz has a long history of advocating for medical marijuana and has introduced several pieces of legislation seeking to loosen laws regulating the drug, both as a state representative in Florida and as a member of Congress.

The former girlfriend was also involved in some of the financial transactions that the FBI has obtained, and investigators are pursuing what knowledge Gaetz had about the payments and activities, sources say. She now works in the Florida state government, according to state records.

Politico first reported that the ex-girlfriend was connected to the Gaetz investigation and went on the Bahamas trip.

In 2017, the woman was interning for a Republican lawmaker when she was fired from the office because she was a Democrat, according to a congressional source. Gaetz then went to a fellow Florida congressman, Democratic Rep. Darren Soto, and asked if he would hire her as an unpaid intern after she had lost her job due to her party affiliation, the source said.

Soto agreed to hire the intern, and she worked for the Florida Democrat for the summer without issue, the source said.

“She was just an intern,” Soto said in a statement to CNN. “I found it offensive that she was fired for her political beliefs.”

Waiting on a Greenberg plea

Regardless of whether the former girlfriend cooperates with investigators, they could soon officially gain the cooperation of Greenberg, Gaetz’s former associate and a Florida county tax collector who is negotiating a plea deal with the government over the 33 charges he’s facing, including sex trafficking a minor.

CNN has previously reported that Greenberg has been speaking with federal investigators since last year, including providing information about how he and Gaetz had encounters with women who were then given cash or gifts for sex.

Greenberg’s lawyer said in a court hearing last month that Greenberg intended to plea, which is expected to include a cooperation agreement with the government. The deadline set by the judge for the two sides to reach a deal is approaching at the end of this week, though the agreement has yet to be finalized.

CNN previously reported Gaetz and Greenberg used digital payment applications to send hundreds of dollars to at least one woman who attended parties in the Orlando area, which included young women, drugs and sex. The receipts viewed by CNN include payments that took place between 2018 and 2019. At least one of those payments indicated in a label that it was to compensate for travel.