Sidney Blumenthal, a top adviser to Bill and Hillary Clinton, was called out on CNBC's Squawk Box Thursday for calling the investigation into Hillary Clinton's use of a private email server what it is: an investigation.

Hillary Clinton has consistently referred to the federal probe as a "security review."

"You met with the FBI about the emails?" co-host Michelle Caruso-Cabrera asked.

"Um, well, as I've said, I can't comment on an ongoing investigation," Blumenthal said.

"Well, at least you called it an investigation," co-host Joe Kernen said. "So, you're off the reservation there. So, it's not just the, what did she call it? A security review, I think. Because Comey yesterday said, ‘I don't even know what that is.’"

"There's the word, investigate, is in FBI, Federal Bureau of Investigation. This is an investigation, so we cleared that up," Kernen said. "And you know, certain news networks have gone back and framed the ten or fifteen times she has said either security review or security, and play it one after another and then they superimpose Comey saying it is an investigation."

While speaking with reporters on Wednesday, FBI Director James Comey gave rare comments on the Clinton email investigation, also disputing the term "security review:"

There’s no special set of rules for anybody that the FBI investigates," Comey stated when questioned about complaints from some individuals with security clearances who have alleged that they would be put in prison for acting as Clinton did. Comey did not provide details about the current status of the investigation into Clinton’s email and described it as "ongoing." According to recent reports, the FBI has interviewed some of Clinton’s former top aides, including Huma Abedin and Cheryl Mills, as it nears the end of the probe. FBI investigators are also reportedly hoping to interview Clinton in coming weeks. Clinton and her presidential campaign have sought to downplay the investigation, describing it as a "security inquiry." However, Comey appeared to dispute that characterization during the discussion with reporters on Wednesday. "It’s in our name. I’m not familiar with the term ‘security inquiry,’" Comey said, describing the probe as an "investigation."

Update: This article earlier mistakenly identified Michelle Caruso-Cabrera as Becky Quick.