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The chairman of a House panel investigating the deadly attacks in Benghazi, Libya, says that a longtime confidant of Democratic presidential candidate Hillary Rodham Clinton did not write any of the numerous memos he forwarded to Clinton while she served as secretary of state.

Nearly all the memos forwarded by Sidney Blumenthal to Clinton came from a single source, Rep. Trey Gowdy, R-S.C., said late Tuesday.

Blumenthal, meeting with reporters after his testimony ended after nearly nine hours at the Capitol late Tuesday, said the memos were written by a former high-ranking CIA official, adding that he passed them on to Clinton as a friend. Blumenthal and Gowdy declined to name the author of the memos, but emails released last month show at least one memo written by former CIA official Tyler Drumheller.

The evening after the September 2012 Benghazi attack, according to the Associated Press, Blumenthal forwarded to Clinton an analysis of the situation from Drumheller which purported to contain information from "sources with direct access to the Libyan National Transitional Council as well as the highest levels of European governments as well as Western intelligence and security services."

The memo said a top Libyan official, Mohamed Yousef el-Magariaf, had told close associates that the Benghazi attack was carried out by the militant group Ansar al-Sharia and that Libyan security officials believed the group "took advantage of cover provided by" demonstrations against an Internet video seen as insulting to the Prophet Mohammed to conduct it.

RELATED:State Department Releases Hundreds of Clinton’s Emails on Libya

Blumenthal said his appearance before the committee was politically motivated.

"My testimony has shed no light on the events of Benghazi, nor could it because I have no first hand knowledge of what happened there," he told reporters after his deposition. "The committee spent hours asking me questions that have nothing to do with Benghazi. Many of the questions had to do with politics as far back as the 2008 Democratic primary."

"So why was I subpoenaed at all before this committee? I am a longtime friend of Hillary Clinton," he added. "It seems obvious that my appearance before this committee was for one reason and one reason only and that reason is politics."

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Earlier in the day, outspoken Republican Congressman Darrell Issa tried to crash the deposition on Benghazi, but was promptly escorted out from the closed-door panel on Capitol Hill.

Gowdy had no qualms about personally kicking out Issa, the former House Oversight Committee chairman.

"I'm a prosecutor, we always follow the rules," Gowdy later told NBC News. "[Issa] is not a [Benghazi] committee member and non-committee members are not allowed in the room during the deposition. Those are the rules and we have to follow them, no exceptions made."

The moment just after Issa was booted from the room was also caught on camera. Gowdy threw his hands up as Issa, R-Calif., stormed off.

Rep Issa (R-CA) walks into Benghazi Cmte deposition of Sid Blumenthal. 30 seconds later Gowdy walks him out. https://t.co/Qyc5mYGvQQ — Frank Thorp V (@frankthorpNBC) June 16, 2015

Issa previously conducted an investigation into the deadly 2012 attack on the U.S. consulate in Benghazi, Libya, in which critics have said the Obama administration and former Secretary of State Hillary Clinton misled Americans about what happened.

At the time of Tuesday's deposition, Issa tried to sit in on Blumenthal, a longtime Clinton confidant, who was asked by the congressional panel about the nearly 60 emails he sent to Clinton.

Those emails will be released in accordance with congressional rules, Gowdy told reporters late last week.

Last month, the State Department released more than 800 pages of emails sent and received on Clinton's private email server during her tenure as secretary of state.

The documents span a two-year period from January 2011 to December 2012 and include emails exchanged about Libya leading up to and including the time of the Benghazi attacks. Some of the emails are heavily redacted.

Clinton has come under fire for using the private server and a personal email account rather than a government address to conduct official business. The State Department is releasing the vetted documents at the request of journalists and Clinton herself, who has said that she wants them to be made public.

Gowdy said he found the release of the new emails important.

“I think it's noteworthy that no committee of Congress that has previously looked into Benghazi or Libya has uncovered these memos, and I will leave it to you to figure out there was a failure to produce on the former secretary's part, or a failure to produce on the Department of State's behalf,” he told reporters on Tuesday.

Rep. Elijah E. Cummings, the committee’s ranking Democrat, questioned Gowdy’s assertions.

“The Select Committee is now conducting its investigation by leaks and press releases, without bothering to mention that these documents don't identify any smoking gun about the Benghazi attacks — in fact, they hardly relate to Benghazi at all,” Cummings said in a statement.

A State Department official confirmed that it has not been contacted by the congressional committee regarding the documents, but that it is "working diligently" to publish all of Clinton's emails online.