Tyler Drumheller Was the Man Behind Hillary Clinton's Private Libya Intel, Sources Say Sources say Tyler Drumheller provided the memos to Clinton.

 -- Former Secretary of State Hillary Clinton had access to the world’s top intelligence agencies and their resources, but at the most turbulent moment of her tenure as the nation’s top diplomat, she received a stream of intelligence on Libya and the Benghazi attack by a former CIA official working outside the government, sources said.

Sidney Blumenthal, a confidant who was paid by the Clinton Foundation, told the Select Committee on Benghazi Tuesday that the information he supplied the sitting Secretary of State came from a “respected former high-ranking CIA official,” rankling Republicans charged with investigating the events around the embassy attack.

“We have a CIA, so why would you not rely on your own, vetted, sourced intelligence agency?” Rep. Trey Gowdy (R-SC), the chairman of the House Select Committee on Benghazi, asked reporters Tuesday.

Sources close to the Benghazi investigation identified the official as Tyler Drumheller, a 25-year veteran of the CIA who retired from the agency in 2005 and has since worked in private consulting.

In 2011 and 2012, sources say Drumheller wrote two dozen memos regarding Libya and the Benghazi attack, mainly about the civil war.

Though Drumheller, 63, was not available to speak with ABC News and did not respond to requests for comment, public information and the memos sources say he composed provide insight into his background.

His wife declined to comment and he has not been accused of any wrongdoing.

A Bush Administration Critic (and Democratic Donor)

After retiring from the CIA, Drumheller emerged as a vocal and high-profile critic of the second Bush administration’s post-9/11 intelligence analysis and push to invade Iraq.

In his 2006 account of the buildup to the Iraq war, he accused the administration of allowing politics to distort intelligence assessments, including the vetting of testimony used by the government to make the claim that Saddam Hussein had a biological weapons program.

“Never before have I seen the manipulation of intelligence that has played out since Bush took office,” he told the German magazine Der Spiegel in 2007.

Since his retirement, Drumheller has also contributed to various Democratic politicians, according to records maintained by the Center for Responsive Politics. In 2005, he contributed a combined $800 to the Senate campaigns of former Sens. Mark Pryor and Mary Landrieu, and donated $500 to Rep. Bill Pascrell, D-New Jersey, in 2011, the Center for Responsive Politics said.

Clinton Valued His Intelligence (But Didn’t Always Agree With It)

Clinton often sent Drumheller’s memos to aides with instructions to print, or “distribute as you determine,” according to emails released by the State Department. While some featured approving commentary (“very interesting,” she wrote on an August 2012 memo on Libya’s new president), others were met with more skepticism (“This one strains credulity,” she wrote of a March 2012 memo claiming France and the United Kingdom engineered Libya’s civil war.)

Gowdy also had doubts about the information supplied by Drumheller.

“I wanted to probe the reliability, the efficacy, the credibility of that information,” he said. “I'm interested in the reliability of the underlying information that was being presented to our top diplomat.”