Rep. Katie Hill denies sexual relationship with one of her congressional staffers

The House Ethics Committee has opened an investigation into allegations that freshman Rep. Katie Hill, a California Democrat and rising star in the House, engaged in a sexual relationship with one of her Capitol Hill staffers in violation of House rules, the panel announced Wednesday.

In a letter her campaign sent to constituents and supporters Wednesday, Hill denied the allegations that she engaged in a sexual relationship with a staffer in her congressional office, but admitted to an “inappropriate” relationship with a campaign staffer during her run for office last year.

“I know that even a consensual relationship with a subordinate is inappropriate, but I still allowed it to happen despite my better judgment,” Hill, who is the first openly bisexual member of Congress, wrote. “For that I apologize. I wish nothing but the best for her and hope everyone respects her privacy in this difficult time.”

She said she would cooperate with the House investigation.

House members are prohibited from engaging in sexual relationships with congressional staffers in their offices or on the committees on which they serve, under a House rule put in place in 2018, after a series of sexual harassment allegations forced nearly a dozen lawmakers from office and re-election bids as the #MeToo movement reverberated on Capitol Hill.

The rule does not apply to campaign staffers, according to campaign finance experts.

The Ethics Committee noted that the investigation “does not itself indicate that any violated has occurred.”

Hill also said in her letter to supporters that she had notified Capitol Police about a blog post on conservative website RedState that published intimate photos of Hill. The site first publicized allegations that she was having an affair with a congressional staffer, and had engaged in a relationship with a female campaign staffer.

Hill said the allegations and photos stemmed from a bitter divorce battle with her “abusive husband who seems determined to try to humiliate me.”

“Distributing intimate photos with the intent to publish them is a crime, and the perpetrator should be punished to the full extent of the law,” she wrote. “I have notified Capitol Police, who are investigating it, and therefore will have no further comment on the matter.”

A Capitol Police spokeswoman declined to comment on the investigation Thursday.

Hill is a vice chair of the House Oversight Committee and freshman representative to House Democratic leadership, elected by her peers to attend House leadership meetings on their behalf.

She has privately denied the allegations of an affair with a staffer to House Speaker Nancy Pelosi and Majority Leader Hoyer, according to aides.

If an investigation substantiates the allegations about the office staffer and Hill’s House colleagues deem her alleged misconduct to be unworthy of the “spirit and the letter of the Rules of the House,” she could be censured, reprimanded, or formally removed from office by a two-thirds vote of the chamber. In cases where lawmakers find evidence of criminal wrongdoing, the House could move to refer any evidence found to state, local or federal authorities.

On Thursday, DailyMail.com published a second series of intimate photos of Hill. Her office did not respond to a request to comment on the photos, but did send a cease and desist letter to the DailyMail.com, requesting they immediately remove the photos from the website.

"California law provides private causes of action against the publication of such photos," Hill's lawyer wrote, adding that the website's claims were false and defamatory, and the continued publication of these images could "warrant legal response."

DailyMail.com did not immediately respond to an ABC News request for comment.