Rep. Katie Hill, D-Calif., has announced her resignation after a series of reports sparked a House Ethics Committee investigation.

Hill tweeted on Sunday evening, "It is with a broken heart that today I announce my resignation from Congress. This is the hardest thing I have ever had to do, but I believe it is the best thing for my constituents, my community, and our country." She is expected to step down by the end of this week.

Hill, who is openly bisexual, had fought back against reports of an affair with her legislative director, as well as reports she was in a "throuple" relationship with husband Kenny Heslep and a campaign staffer.

House Speaker Nancy Pelosi released a statement saying, "Congresswoman Katie Hill came to Congress with a powerful commitment to her community and a bright vision for the future, and has made a great contribution as a leader of the Freshman class."

"She has acknowledged errors in judgment that made her continued service as a member untenable," Pelosi wrote. "We must ensure a climate of integrity and dignity in Congress, and in all workplaces."

Last week, The Daily Mail published a photograph allegedly showing Hill undressed and holding a bong, and another of her kissing the campaign staffer.

"This is what needs to happen so that the good people who supported me will no longer be subjected to the pain inflicted by my abusive husband and the brutality of hateful political operatives who seem to happily provide a platform to a monster who is driving a smear campaign built around cyber exploitation," Hill wrote in her resignation letter.

She continued, "Having private photos of personal moments weaponized against me has been an appalling invasion of my privacy. It's also illegal, and we are currently pursuing all of our available legal options."