Washington (CNN) The top House Republican investigating the attacks in Benghazi told CNN on Tuesday that he plans to release new emails between former Secretary of State Hillary Clinton and a close ally "sooner rather than later."

House Benghazi Committee Chairman Trey Gowdy said that his committee received about 60 new emails from Clinton confidant Sidney Blumenthal ahead of his closed-door deposition with committee members Tuesday.

The top Democratic on the panel, Maryland Rep. Elijah Cummings, said Gowdy should release the entire transcript of Blumenthal's deposition along with the emails to provide proper context.

Gowdy said he is open to Cummings' request but said he's "releasing the emails no matter what."

"I need him to explain to me why this witness should be treated differently than any other witness," said Gowdy, noting that other witness transcripts have not been made public.

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For his part, Cummings said, "I'm 100 percent for releasing the Blumenthal documents only if there is also the release of the transcript of today's deposition."

He acknowledged that Democrats don't have the ability to release the transcript without the GOP's consent.

Blumenthal produced the latest emails, which number about 120 pages, in response to the committee's request.

The committee is interested in Blumenthal's emails to Clinton, which often contained memos that read like intelligence reports. The emails have drawn scrutiny because Blumenthal sent them while advising businesses interests in Libya and working with the Clinton Foundation.

Clinton has said that Blumenthal's emails were "unsolicited." But a source who has been briefed on the new Blumenthal emails told CNN the new batch calls that explanation into question.

Gowdy called the new emails "eerily similar" to the ones the committee received previously.

"The committee is interested in what role he played at the State Department and how his role was financed. Who was paying him, and who was he paying? Basically, his business arrangements," said a source familiar with the committee's thinking.

During breaks in the deposition Tuesday, Blumenthal and Gowdy described the tone of the meeting as "civil." Blumenthal, who has not yet spoken to reporters, told CNN he "should be able to" make a statement after the deposition concludes.

Democrats have complained that the committee has drifted from its mission of investigating the attacks in Benghazi and has become an inquest into Clinton, the frontrunner for the Democratic presidential nomination.

Cummings on Tuesday recycled a line Democrats have used to describe other committee findings, saying the new emails don't provide "smoking gun" evidence that Clinton mismanaged the mission in Benghazi or the aftermath of the 2012 attacks that left four Americans dead.

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Or, as Democratic committee member Rep. Adam Schiff put it, "If the witness (Blumenthal) wasn't close to the Clintons, there's no way he would be here today."

Earlier this year, the State Department turned over about 300 Benghazi-related emails to the committee. Cummings said one explanation for why Blumenthal produced different emails than the State Department might be that the committee made different requests of the two.

Alec Gerlach, a State Department spokesman, said the department would need to see the emails in order to respond to the discrepancy. The committee, he said, has not yet contacted the State Department about the emails.

"The department is working diligently to publish to its public website all of the emails received from former Secretary Clinton through the FOIA process. We provided the committee with a subset of documents that matched its request and will continue to work with them going forward," he said. "Secretary Kerry has been clear that the State Department will be both transparent and thorough in its obligations to the public on this matter."