Rep. James Comer said the evidence against Hunter Biden is "overwhelming" and called him a "national security threat" Thursday.

"The walls are caving in on Hunter Biden," the Kentucky Republican said on "The Ingraham Angle." 

Even Democrats are starting to realize the threat Hunter poses to U.S. national security, Comer said. 

"In reality, the Democrats know Hunter Biden is a problem. They're starting to realize that he is a national security threat."

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Hunter Biden and Rep. James Comer

Hunter Biden and Rep. James Comer  (Jim Lo Scalzo/EPA/Bloomberg via Getty Images | Fox News )

"Hunter Biden is a national security threat and what we've learned in the last few days is that this just wasn't Hunter Biden," he said. "This also included James Biden, the president's brother. And you know, the big question is, who's the ‘big guy’? And does it go all the way to the top?

Comer said Republicans want Hunter to testify before Congress to explain possible red flags in transactions. 

"It appears that Hunter and James Biden have had 150 SARs filed against them," he said, referring to suspicious activity reports.

Joe Biden's brother-in-law, Jack Owens, emailed Hunter in 2014 to help him obtain a Chinese business license.

Joe Biden's brother-in-law, Jack Owens, emailed Hunter in 2014 to help him obtain a Chinese business license. (Photo by Teresa Kroeger/Getty Images)

"You don't just nonchalantly file a SARs against someone," he said. "These guys have a suspicious record of financial transactions in multiple countries, and these are countries that could compromise the president of the United States."

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Democrats won't be interested in investigating the matter until after the midterm elections in November, Comer said.

Biden delivers remarks from the White House

President Joe Biden delivers remarks at the White House, Monday, Oct. 4. (AP Photo/Evan Vucci)

"The evidence against Hunter Biden is overwhelming," he told host Laura Ingraham. "I think every rational American now sees it."