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The federal investigation of Rep. Matt Gaetz (R-Fla.), said to center on possible sex-trafficking violations and sex with a 17-year-old girl, has branched out to include a trip to the Bahamas with well-connected GOP allies and allegedly paid female companions plus whether Gaetz was involved in running a third-party "ghost" candidate in a state Senate race to help an associate, The New York Times reports.

Gaetz has denied paying for sex or having sex with a 17-year-old girl, but his alleged partner in procuring women for sex, Joel Greenberg, is now expected to plead guilty and potentially flip on Gaetz, Greenberg's lawyer and federal prosecutors suggested Thursday. One congressional Republican, Rep. Adam Kinzinger (R-Wash.), has called on Gaetz to resign, and Gaetz's legislative director, Devin Murphy, abruptly quit last week, the Times reports.

Investigators are in the early states of their inquiry into whether Gaetz worked with prominent Florida lobbyist Chris Dorworth to put a sham third-party candidate in a state Senate race to help a Gaetz associate, Jason Brodeur, beat a Democratic rival for an open seat, the Times reports. Recruiting a "ghost" candidate to swing a race against an opponent is generally legal, but secretly paying them to do so is frowned upon, legally speaking. In Brodeur's case, a third candidate did run but barely campaigned, and fliers depicted her as a Democrat, like Brodeur's opponent.

Brodeur ultimately raised more than $3 million for the race and won by 7,600 votes; the third-party candidate, Jestine Iannotti, got 6,000 votes. Brodeur told the Times through a spokeswoman he had nothing to do with the Iannotti fliers and Dorworth said he never met, communicated with, or paid Iannotti, and doesn't recall discussing running a third-party candidate with Gaetz.

"A ghost candidate scheme would be brazen even in Florida, which has been fertile ground for unseemly political ploys," the Times reports, though two little-known third-party candidates in Miami races last election did help Republicans win and keep control of the state Senate. "In one of the Miami races, which was decided by 32 votes, an accused ghost candidate and a campaign backer have been indicted on campaign finance charges."