Washington — Connecticut Congressman Jim Himes, the second-highest ranking Democrat on the House Intelligence Committee, accused the top Republican on the panel, Congressman Devin Nunes, of promoting conspiracy theories to defend President Trump and cast doubt on Russian meddling in the 2016 presidential election.

"If you watched Devin Nunes for five minutes in these hearings, you know that he has given over to the, utterly, to the defense of the president and more importantly, to the propagation of fantastical conspiracy theories," Himes said on "Face the Nation" Sunday.

Himes said Nunes, one of the most ardent congressional allies of the White House during the impeachment inquiry, has been pushing a dubunked theory that Ukrainian officials meddled in the 2016 presidential election to hurt Mr. Trump's candidacy. The theory is at the center of efforts spearheaded by Rudy Giuliani to oust Marie Yovanovitch as U.S. ambassador to Ukraine earlier this year.

"This whole Ukrainian meddling in the election of 2016 has zero evidence for it, and it is deliberately propagated by the Russian state in order to create confusion," Himes said.

Multiple assessments by the intelligence community, special counsel Robert Mueller and congressional committees have found that the Russian government staged a sophisticated campaign to interfere in the 2016 election and sow discord in the U.S.

As ranking member of the intelligence committee, Nunes repeatedly defended the president during the public impeachment inquiry hearings that concluded last week, accusing Democrats of propagating "conspiracy theories" themselves.

The California Republican is now facing allegations, first reported by The Daily Beast and CNN, that a now-indicted Giuliani associate helped arrange meetings for Nunes and a group of staffers with Viktor Shokin, Ukraine's former top prosecutor, in Vienna last year, an apparent attempt to dig up political dirt on Joe Biden. A lawyer for Lev Parnas, the Ukrainian-American businessman who helped Giuliani push conspiracy theories, told CNN his client was ready to tell Congress about his role in arranging the alleged communications between Nunes and the ex-Ukrainian prosecutor.

Himes on Sunday said he did not know if the allegation was true. But he said testimony by Parnas would help Congress look into it.

"Is it credible? Look, I don't know what happened on that trip, 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," Himes said. "That's actually what the president is accused of doing, misusing public dollars for a political purpose."

"I haven't seen evidence one way or the other, but obviously Mr. Parnas may be able to cast some light on that," he added.

Nunes declined to comment on the allegations in an interview on Fox News' "Sunday Morning Futures" on Sunday, saying he planned to take legal action against CNN and The Daily Beast.