The top Republican on the House Intelligence Committee said reports that he met with ex-Ukrainian prosecutor general Viktor Shokin in Vienna last year were false, but declined to elaborate in an interview on Fox News.

The allegation that Rep. Devin Nunes (Calif.) met with Shokin to obtain information about former vice president Joe Biden and his son was made by the attorney for Lev Parnas. Parnas is one of two Soviet-born associates of Rudolph W. Giuliani who were indicted on charges that they broke campaign finance law.

Parnas’s attorney, Joseph Bondy, told The Washington Post that Shokin informed Parnas that he had met with Nunes in Vienna in December 2018.

On Fox News, Nunes declined to answer further questions about the accusation, which he previously dismissed as “demonstrably false and scandalous” in an interview with the conservative outlet Breitbart News. A person close to Shokin also has denied the claim.

Speaking to host Maria Bartiromo on Fox News Channel’s “Sunday Morning Futures,” Nunes said: “I really want to answer all of these questions, and I promise you I absolutely will come back on the show . . . but I think you can understand that I can’t compete by trying to debate this out with the public media when 90 percent of the media are totally corrupt.”

Nunes has also threatened to sue two of the news outlets that reported Parnas’s accusation. On Fox News, Nunes claimed that CNN and the Daily Beast were “likely conspiring to obstruct justice” by basing their reporting on interviews with a lawyer for Parnas.

“It’s so slanderous,” Nunes said. “We’ve got all the facts on our side, and we’re going to file in federal court. . . . I will win in court and they [CNN and the Daily Beast] will have a chance to cooperate, and they’ll have to show how they worked with somebody who has been indicted, which is likely conspiring to obstruct justice here.”

Nunes said he planned to file “right after Thanksgiving.”

In an email statement to The Washington Post, the Daily Beast said: “We don’t comment on threats of litigation but stand by our reporting and are happy to defend it.”

A spokesperson for CNN declined to comment.

After Nunes’s interview Sunday, Bondy released a statement saying his client “has vociferously and publicly asserted his wish to comply with his previously issued subpoena and to provide the House Intelligence Committee with truthful and important information that is in furtherance of justice, not to obstruct it.”

Nunes’s remarks came as some top Democrats were asked whether he should face an ethics investigation over the alleged meeting with Shokin, a key figure in Giuliani’s alleged effort to pressure Ukraine’s government to investigate the Bidens.

Shokin was removed from his position in March 2016 amid pressure from Ukraine’s Western allies. He has accused Biden of pushing for his removal to protect his son, Hunter Biden, who served on the board of Burisma, a Ukrainian energy company.

The saga has received fresh attention because of the House’s impeachment inquiry. That probe is focused on whether Trump withheld military aid and a White House meeting from Ukraine to force its government into launching investigations into the Bidens and alleged interference in the 2016 election.

House Armed Services Committee Chairman Adam Smith (D-Wash.) said Saturday that it was “quite likely, without question” that Nunes would face an ethics investigation following media reports of a meeting with Shokin.

But on Sunday, House Intelligence Committee Chairman Adam B. Schiff (D-Calif.) declined to weigh in. “I don’t want to comment on what the Ethics Committee should do, particularly vis-a-vis the ranking member of my committee,” Schiff said on CNN’s “State of the Union.”

Several other Democratic lawmakers have said that Parnas’s testimony could be helpful to impeachment investigators or that Nunes should face an ethics probe.

Rep. Jim Himes (D-Conn.) said Sunday that Nunes has “given over utterly to the defense of the president and, more importantly, to the propagation of fantastical conspiracy theories” about Ukrainian interference in the 2016 election.

“I don’t know what happened on that trip,” Himes told CBS’s “Face the Nation,” “but the allegation is that Devin Nunes used federal funds to fly himself and a couple of staffers over there in the search of dirt on Biden. … Look, I haven’t seen evidence one way or the other, but obviously Mr. Parnas may be able to cast some light on that.”

Rep. Jackie Speier (D-Calif.), a member of the House Intelligence Committee, tweeted Saturday that if Nunes “was using taxpayer money to do ‘political errands’ in Vienna for his puppeteer, Donald Trump, an ethics investigation should be initiated and he should be required to reimburse the taxpayers.”

The same day, Rep. Joaquin Castro (D-Tex.) told NPR that the House Intelligence Committee should hear testimony from Parnas. Castro is also a member of that panel.

“I think it would be valuable to hear from him because we want to know just how far this work extended, how many people were doing the president’s dirty work here,” he told NPR.

Rosalind S. Helderman and Colby Itkowitz contributed to this report.