(CNN) The Republican-controlled Senate Intelligence Committee looked into allegations that Ukraine interfered in the 2016 election and found no evidence to support the claims , according to sources familiar with the matter.

This squares with the overall conclusion of officials who have looked into the matter. Sources tell CNN that no US intelligence agency has ever produced a product accusing the Ukrainian government of interfering in the 2016 US election.

Some Republican lawmakers continue to misleadingly say that the government of Ukraine interfered in the 2016 election on the same level as Russia, despite the GOP-led committee looking into the matter and finding little to support the allegation. The committee went so far as to interview former Democratic National Committee operative Alexandra Chalupa -- a central figure in theories that say Ukraine interfered in the election -- before closing that aspect of their probe, according to the sources. Politico on Monday was first to report the committee's exploration of Ukraine's actions in 2016.

The committee looked into any possible Ukrainian interference because -- as committee Chairman Sen. Richard Burr, a North Carolina Republican, told reporters on October 4, 2017 -- the investigation was to look into a number of measures, including "any collusion by either campaign during the 2016 elections."

Twelve days after he said that, sources tell CNN, Chalupa met with staffers on the committee for a more-than-two-hour meeting covering a range of subjects, including why she was so alarmed in 2016 to learn that candidate Donald Trump had hired Paul Manafort, who worked with corrupt Ukrainian President Viktor Yanukovych.

Chalupa was never called back before the committee and investigators considered the matter closed, sources say. Chalupa could not be reached for comment.

Burr told CNN that some officials from Ukraine actively supported Hillary Clinton but "I don't think anybody interfered in the same way Russia did."

Burr wouldn't comment when asked about Chalupa's testimony.

Sources familiar with the matter say that on October 5, 2017, the committee also interviewed Shawn Henry, the president of Crowdstrike Services, the cybersecurity company that has become a focus of conspiracy theorists on the matter including Trump. Henry declined to comment when reached by CNN.

Sen. Marco Rubio, a Florida Republican who's a member of the Senate Intelligence Committee, also told CNN there's "nothing that compares to the Russian effort," adding that what Ukrainian officials did is "nothing close" to the extensive Russian effort and it's "not even in the same universe."

Members of the Senate Intelligence Committee are careful about what they say publicly about committee matters, but Sen. Angus King, a Maine independent, told CNN, "I've been in probably 25 hearings and briefings on the Senate Intelligence Committee over the past three years on the subject of the 2016 election -- including updates from staff on the committee -- and I have never heard anything about any engagement by Ukraine in the 2016 election."

Sen. Mark Warner, a Virginia Democrat who is the ranking member on the committee, refused to comment specifically on whether the committee had investigated if Ukraine interfered in the 2016 election. But he emphasized to CNN that Russia was responsible for the 2016 election interference.

"I stand by the bipartisan Senate Intelligence Committee investigation, which confirmed the Intelligence Committee's assessment that it was Russia," Warner said. "I stand by the Mueller report, which confirms that it was Russia that intervened. I stand by Mr. Trump's appointees as head of the CIA, head of the FBI, director of national intelligence, who have all testified publicly that it was Russia."

Republican accusations of Ukrainian election interference include what former Trump homeland security adviser Tom Bossert has called a debunked conspiracy theory -- that it was Ukraine, not Russia, that actually did the hacking of the DNC server.

GOP officials have also accused Ukraine of interfering in the 2016 election because some officials in the Ukrainian government publicly criticized Trump and supported Clinton, which intelligence and national security officials widely do not consider to be "interference" in an election.

The conspiracy theory that Ukraine, not Russia, interfered in the US election was pushed publicly by Russian President Vladimir Putin in February 2017 and has been since pushed by Trump, his attorney Rudy Giuliani, and -- most recently -- Sen. John Kennedy, a Republican of Louisiana.

Still, Republican lawmakers have increasingly attempted to equate the actions of the two countries even though no intelligence community report has ever accused Ukraine of interfering in the election, sources tell CNN.

Trump's former Russia expert Fiona Hill testified last month that there had been comments by various Ukrainian government officials, including the Ukrainian ambassador to the US, who in 2016 took issue with candidate Trump's pronouncements on Ukrainian issues.

"They bet on the wrong horse," Hill said. "They bet on Hillary Clinton winning the election. And so, you know, they were trying to curry favor with the Clinton campaign -- it's quite evident here." But she said that's not the same as what Russia did in 2016.

In recent weeks, Republican lawmakers have increasingly floated that Ukraine interfered in the 2016 election despite the conclusions of the intelligence community that Russia alone was responsible.

Most notably it's Kennedy, an outspoken Louisianan, who has grabbed headlines for his statements about the 2016 election. Kennedy first said last month on Fox News that it could have been Ukraine and not Russia who interfered in the election. He later backtracked on those comments to CNN's Chris Cuomo and said he was wrong.

But on Sunday, he said he now thinks both Russia and Ukraine interfered in 2016.

"I think both Russia and Ukraine meddled in the 2016 election. I think it's been well documented in the Financial Times, in Politico, in The Economist, in the Washington Examiner, even on CBS, that the prime minister of Ukraine, the interior minister, the Ukrainian ambassador to the United States, the head of the Ukrainian Anti-Corruption League, all meddled in the election on social media and otherwise," Kennedy said on NBC's "Meet The Press."

Other Republican lawmakers haven't been as explicit in support of the conspiracy theory. Some, like Sen. John Cornyn of Texas, wouldn't rule it out, though.

"I can't talk about things I see in a classified setting in the Intelligence Committee, but I think it's fair to say other countries over a long period of time in the past and I anticipate for a long time in the future will try to sow discord and disinformation and get involved in the US elections," Cornyn said on Monday when asked by CNN if he had seen any evidence that Ukraine interfered in the 2016 election.

Asked if he knew of any intelligence agencies that said Ukraine had interfered in the election, Cornyn said, "Well, I believe there was some open-source reporting to the effect there were actors in Ukraine actively encouraging the Clinton campaign."

Even Burr wasn't immune to attempting to walk a fine line that wouldn't contradict the President.

"But it's a legitimate argument that they interfered -- that they were active," Burr told CNN, in another example of Republicans attempting to muddy the water when it comes to Ukraine and the 2016 election.