Representative Matt Gaetz’s push to oust Speaker Kevin McCarthy has cemented his status as one of the most reviled members of the House of Representatives — including among many of his fellow Republicans — and drawn attention to a long-running investigation by the House Ethics Committee into his conduct.
Mr. McCarthy has argued that Mr. Gaetz’s attempt to remove him as speaker is little more than personal payback for Mr. McCarthy’s failure to interfere with the inquiry, which is looking into allegations of sexual misconduct and misuse of funds by Mr. Gaetz, a Florida Republican.
Mr. Gaetz has asserted that the more than two-year, wide-ranging inquiry into his conduct is the work of the speaker and his allies, who he argues are bent on smearing him.
“I am the most investigated man in the United States Congress,” Mr. Gaetz said Monday night of the ethics inquiry, adding: “It seems that the Ethics Committee’s interest in me waxes and wanes based on my relationship with the speaker.”
He posted a picture on social media on Sunday of himself glowering as more than a dozen guns were being pointed at his head.
Since the spring of 2021, Mr. Gaetz has been under investigation over allegations he engaged in sexual misconduct and illicit drug use, shared inappropriate images or videos on the House floor, misused state identification records, converted campaign funds to personal use and accepted impermissible gifts under House rules, among other allegations.
The secretive congressional investigation was paused while the Justice Department carried out a related investigation of Mr. Gaetz’s conduct, including allegations involving sex trafficking and sex with a minor. In February, the Justice Department decided not to bring charges against Mr. Gaetz after concluding they could not make a strong enough case in court.
Once the Justice Department inquiry ended, the Ethics Committee resumed its work, according to people familiar with the matter, reaching out to witnesses for interviews. However, a person familiar with the matter said the committee, which is made up of an equal number of Republicans and Democrats, has not yet reached out to a key witness at the center of the most serious allegations against Mr. Gaetz.
The people familiar with the situation spoke about the investigation on the condition of anonymity because it is confidential.
Once he learned of the resumed investigation, Mr. Gaetz began complaining to some of his Republican colleagues about it, according to people familiar with the matter.
Mr. McCarthy has repeatedly suggested the Ethics Committee investigation prompted Mr. Gaetz to lash out at him, blaming him for the inquiry.
“The Ethics complaint against Matt happened in the last Congress,” Mr. McCarthy said on Fox News on Monday, adding: “It would be illegal for me to do anything in that committee.”
Even so, Mr. McCarthy said he knew of emails in which Mr. Gaetz stated that he believed the speaker was behind the inquiry.
“Legally, I can’t do anything and I’m not going to do anything,” Mr. McCarthy said.
Whatever the outcome of the investigation, as Mr. Gaetz has pressed his challenge to Mr. McCarthy in recent days, many Republican allies of the speaker have vented their frustration publicly with his most outspoken tormentor.
“I think he’s a petulant child,” Representative Mike Lawler, Republican of New York, said on CNN, adding: “He doesn’t care about governing. He cares about getting attention.”
In an interview, Representative Derrick Van Orden, Republican of Wisconsin, referred to Mr. Gaetz as “some guy from Florida” and questioned why anyone would listen to him.
“This is just foolishness, and I’ll have no part in it,” he said of Mr. Gaetz’s actions.
The Ethics Committee is likely to write a report detailing its findings against Mr. Gaetz, but it was unclear how long that would take. The panel could recommend a range of punishments depending on what facts its investigators uncover.
Mr. Gaetz said he would not back down.
“I believe that Speaker McCarthy is trying to signal to the Ethics Committee to pursue me,” he told reporters Monday, adding: “I’m built for the battle. I’ve faced down tougher than these folks, and I’ll do it again.”