(Peter Stevenson/The Washington Post)

House Intelligence Committee Chairman Devin Nunes (R-Calif.) temporarily stepped aside Thursday from the committee’s probe into Russian interference in the presidential election, as House investigators look into ethics charges against him.

The House Ethics Committee released a statement Thursday saying it had “determined to investigate” allegations that “Nunes may have made unauthorized disclosures of classified information, in violation of House Rules, law, regulations, or other standards of conduct.”

Nunes has come under fire in recent weeks for speaking publicly about classified foreign surveillance reports he viewed on White House grounds. Nunes suggested that those reports identified President Trump and members of his transition team, whose names may have been mentioned by individuals under surveillance — or whose conversations with those individuals may have been incidentally picked up.

On Thursday, Nunes dismissed the suggestion that he violated ethics laws as “entirely false and politically motivated,” blaming “several left-wing activist groups” for filing complaints with the Office of Congressional Ethics. He noted that he asked to speak with the Ethics Committee “at the earliest possible opportunity in order to expedite the dismissal of these false claims,” and said his recusal — which applies only to the committee’s Russia investigation — would be in effect while the committee looks into the matter.

Nunes for weeks has resisted calls from Democrats to step aside. It was not clear Thursday whether his reversal was prompted by the Ethics Committee’s investigation — which was revealed just moments after Nunes made his announcement — or resulted from pressure from House leaders.

In the meantime, Rep. K. Michael Conaway (R-Tex.) will take the lead on the Russia investigation, Nunes said, with assistance from Reps. Thomas J. Rooney (R-Fla.) and Trey Gowdy (R-S.C.). Gowdy also sits on the Ethics Committee. Nunes also pledged in his statement to “continue to fulfill all my other responsibilities as Committee Chairman” in matters unrelated to the Russia probe.

House Speaker Paul D. Ryan (R-Wis.) said Thursday that he does not think Nunes did anything wrong, but he “fully support[s] his decision.”

“Chairman Nunes wants to make sure he is not a distraction to this very important investigation,” Ryan said.

The House Intelligence Committee’s Russia investigation all but ran aground last week, after Nunes went to the media — and Trump — with information about the surveillance reports before informing committee Democrats.

“The biggest mistake was not consulting with the Democrats,” said Sen. John McCain (R-Ariz.), who has previously criticized Nunes’s actions, and who applauded his decision to step down. “You have to do that if you’re going to be successful around here, especially on national security issues.”

Democrats accused Nunes, who served on Trump’s transition team, of coordinating the disclosure with the White House, where at least three officials were tied to the files Nunes viewed. Democrats have also accused Nunes of working with the Trump administration to keep former acting attorney general Sally Yates from testifying publicly before the committee.

On March 28, the heads of advocacy groups Democracy 21 and Citizens for Responsibility and Ethics in Washington sent a letter to the Office of Congressional Ethics asking investigators to look into whether Nunes disclosed classified information. It is not clear whether that letter inspired an inquiry.

But the House Ethics Committee cited “public allegations” Thursday in announcing its probe just over two weeks after Nunes’s controversial visit to White House grounds and 10 days after the advocacy groups sent their letter. That is an uncommonly quick turnaround for the committee, which often waits until it receives a formal referral and report from the Office of Congressional Ethics before taking up an inquiry.

The nature of the allegations against Nunes — that he potentially disclosed classified information — are rare, and oblige the committee to look into the matter, under House rules. In its statement, the committee cited an “institutional obligation” to investigate “unauthorized disclosures of classified information.”

Experts said the committee’s quick turnaround also suggests that they may have stepped forward to keep the independent Office of Congressional Ethics at bay — potentially injecting partisanship into the probe by giving it over to an evenly divided panel of lawmakers.

“It’s a way of taking control,” said Bryson B. Morgan, a former investigative counsel with the Office of Congressional Ethics, who explained that the House Ethics Committee can tell the OCE to stand down if it launches an investigation first. He also noted that because the Ethics Committee did not appoint a special panel to conduct the probe, there was no telling how seriously or quickly members planned to dig into the allegations against Nunes.

“It is the black box of congressional ethics investigations,” Morgan said of the Ethics Committee’s chosen category of probe. “You just don’t know what you’re going to get.”

In the meantime, stewarding the House Intelligence Committee’s Russia investigation will fall to Conaway, 68, who also serves as chairman of the House Agriculture Committee. His reputation on Capitol Hill is that of a quiet and diligent lawmaker. Senate Intelligence Committee Chairman Richard Burr (R-N.C.) said he was “more than capable” of carrying out the investigation. In a brief interview, Conaway pledged to work “with my colleagues on the other side of the aisle” to complete the Russia probe.

But Conaway is also a Trump supporter, and he has on various occasions sought to sow doubt about the intelligence community’s conviction that Russia meddled in the 2016 elections to help Trump’s candidacy.

A major part of both the House and Senate intelligence committee investigations involves potential links between Trump’s campaign and transition teams and Russian officials. But when FBI Director James B. Comey and National Security Agency Director Michael S. Rogers endorsed that finding before the House Intelligence Committee in an open hearing last month, Conaway questioned the intelligence community’s rationale.

“The logic is that because [Putin] really didn’t like presidential candidate [Hillary] Clinton that he automatically liked Trump?” Conaway asked Comey. “That might work on Saturday afternoon when my wife’s [Texas Tech] Red Raiders are playing the Texas Longhorns,” he noted but suggested that such logic would not apply “all the rest of the time.”

“It’s based on more than that,” Comey retorted, defending the intelligence community’s logic by continuing the football metaphor. “Whoever the Red Raiders are playing, you want the Red Raiders to win; by definition you want their opponents to lose.”

In the past, Conaway has also said that if Congress wants to probe foreign interference in the 2016 election, it should also look into how “Harry Reid and the Democrats brought in Mexican soap opera stars, singers and entertainers who had immense influence” to help get out the vote in Las Vegas.

Helping Conaway is Gowdy, another Intelligence Committee member who has drawn accusations from Democrats of letting partisanship seep into investigations. That was particularly the case when Gowdy chaired a select committee looking into the deaths of four Americans in Benghazi, Libya, in 2012.

Gowdy also sits on the House Ethics Committee, which is now investigating Nunes over allegations he may have disclosed classified information against House rules.

Mike DeBonis contributed to this report.