Ryan, however, told reporters that he has "seen no evidence to the contrary of the initial assessment that Chairman Gowdy has made." He also cautioned that "we have some more digging to do" before a final determination can be made.

The Wisconsin Republican's solidarity with Gowdy, R-S.C., puts him at odds with President Donald Trump , who has claimed without the support of public evidence that a "spy" embedded in his campaign for "political purposes" could constitute the "all time biggest political scandal!"

House Speaker Paul Ryan said Wednesday that House Oversight Committee Chairman Trey Gowdy was "accurate" when he argued the FBI has acted appropriately in its ongoing probe of potential Russian links to the Trump campaign.

Gowdy has played a significant role in the congressional inquiries regarding Russian meddling in the 2016 presidential campaign, as well as federal investigators' conduct in their investigations.

The South Carolina Republican, who is not seeking another term, was the only member of the House Intelligence Committee's majority to read the underlying source materials used to compile a much-hyped memo alleging surveillance warrant abuses against Trump campaign staff.

He was also among the handful of Republicans selected to attend a confidential briefing two weeks earlier with intelligence officials to discuss the FBI's reported use of an informant who spoke to Trump campaign members as part of the Russia probe.

Days after the meeting, Gowdy said in a Fox News interview, "I am even more convinced that the FBI did exactly what my fellow citizens would want them to do."

He added, "It looks to me like the FBI was doing what President Trump said I want you to do — find it out."

The White House did not immediately respond to CNBC's request for comment.