Rep. Katie Hill, D-Calif., is expected to deliver a farewell address to Congress on Thursday after announcing her resignation last weekend amid a House Ethics investigation following allegations she had inappropriate sexual relationships with a female campaign staffer and her male congressional legislative director.

Reports of money paid to both -- consulting fees for the female staffer and an "election bonus" for the male aide -- have also drawn scrutiny.

The freshman lawmaker will deliver her final address after Congress votes to legitimize -- and set parameters for -- the ongoing House impeachment inquiry into President Trump, USA Today reported. Hill has played a role in impeachment efforts as the vice chair of the House Oversight and Reform Committee and a freshman liaison to Democratic leaders. Her last day in Congress will be Friday, her office said.

KATIE HILL IS 'VICTIM,' SOME MEDIA CLAIM, FOCUSING ON LEAKED PHOTOS OVER REPORTED INAPPROPRIATE RELATIONSHIPS

In an address to her supporters Monday, Hill pledged to fight from outside of Congress against “revenge porn” after nude photos said to be of Hill appeared on the internet. Fox News has not confirmed the authenticity of the photos.

Hill said she would “not allow my experience to scare off other young women or girls from running for office.”  She also slammed “the right-wing media” and her Republican opponents for carrying out a “coordinated campaign” to smear her name and perpetuate what she described as her estranged husband’s abusive behavior toward her.

Hill announced her resignation Sunday after denying she had an inappropriate relationship with her male congressional legislative director, which had prompted a House Ethics investigation. She also admitted she had an "inappropriate" relationship with a female campaign staffer, after a series of leaks of personal texts and photos.

The conservative website RedState.com first reported Oct. 10 that Hill, 32, who is openly bisexual, previously had been involved in a "throuple," or a three-person relationship, with a female campaign staffer and her estranged husband Kenny Heslep, who has since filed for divorce. According to RedState.com, Heslep filed for divorce after learning of Hill’s alleged affair with her male legislative director, Graham Kelly.

Hill never directly accused her estranged husband of leaking the photos. Heslep, who married Hill in 2010, reportedly told his father that he thought his computer had been hacked around the same time the photos surfaced in media reports, according to BuzzFeed News.

Heslep’s father told BuzzFeed on Wednesday that his son denied any role in distributing the photos but said he did not contact law enforcement when he began experiencing computer problems before the RedState.com story was published. RedState.com also published screenshots of a since-deleted Facebook post written by Heslep in which he publicly accused Hill of having an affair with her male congressional staff member. That allegation launched the House Ethics investigation.

Red State and the Daily Mail published nude photos that purportedly show the freshman congresswoman, some with an identified female campaign aide, and one which shows Hill undressed holding a bong. Attorneys representing Hill sent the Daily Mail a cease-and-desist letter, claiming the photos were published without Hill’s permission and threatening legal action if the British tabloid did not remove the images from its website.

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Also Thursday, George Papadopoulos, a former Trump campaign aide who has alleged that he was targeted in FBI’s Russia probe as part of a scheme to take down his boss, is expected to formally announce his candidacy for Hill's seat in California's 25th Congressional District north of Los Angeles. Papadopoulos on Tuesday filed paperwork to run for the seat to be vacated by Hill. He pleaded guilty to lying to the FBI during former Special Counsel Robert Mueller's probe into Russian interference in the 2016 presidential election.

Hill unseated an incumbent Republican in 2018 and is one of the few openly bisexual members of Congress. Since her resignation announcement, three Republicans and one Democrat have said they plan to run for her seat, USA Today reported.

Fox News' Gregg Re, Joseph A. Wulfsohn and The Associated Press contributed to this report.