A longtime confidant to former President Bill Clinton and Democratic presidential candidate Hillary Rodham Clinton faces questions from the Republican-led House panel investigating the deadly 2012 attacks in Benghazi, Libya.

Sidney Blumenthal is scheduled to testify in closed session Tuesday about frequent emails on Libya he sent to Hillary Clinton when she served as secretary of state. Blumenthal worked in the White House under President Clinton and is a longtime friend and adviser to the Clinton family.

Blumenthal’s role in sending the near-monthly missives emerged when nearly 350 pages of emails about the 2012 attacks on the U.S. diplomatic post in Benghazi were publicly released last month. The attacks killed four Americans, including U.S. Ambassador Chris Stevens.

His testimony comes days after Clinton formally kicked off her presidential campaign on Saturday.

A spokeswoman for the committee, Amanda Duvall, said the GOP-led panel “is only interested in the facts,” adding that Blumenthal was called to testify because of the large number of emails he sent Clinton regarding Libya.

Duvall said Blumenthal gave the committee roughly 60 new emails totaling 120 pages last week in response to a request by the committee. The emails are between Clinton and Blumenthal and were not previously produced to the committee or released to the public, Duvall said.

Blumenthal offered a flood of advice and intelligence to his former boss, sending frequent emails about the growing unrest in Libya to the personal email account Clinton continued to use as a government employee. The correspondence, which covered everything from warring Middle Eastern factions to political strategy, was absorbed by Clinton, who often forwarded the messages to aides.

Clinton’s earlier efforts to hire Blumenthal, who has spent nearly two decades working for the Clinton family, as a State Department employee were rejected by White House aides. Those aides feared that Blumenthal’s role spreading harsh attacks against Barack Obama in the 2008 presidential primaries would cause discomfort within the Obama administration.

Rep. Lynn Westmoreland, R-Ga., said he and other committee members want to know the depth of Blumenthal’s involvement in Libya policy, why he had the information and who gave it to him.

The five Democrats on the Benghazi panel said their Republican colleagues were no longer interested in discovering facts about Benghazi, but merely were trying to prove that Clinton “engaged in some sort of conspiracy” over the attacks.

Rep. Elijah Cummings, D-Md., the senior Democrat on the panel, said Blumenthal’s deposition was the latest example of how the committee “has strayed far from investigating the Benghazi attacks and is now focused like a laser on attacking Secretary Clinton in her run for president.”

Cummings called it a “travesty” that the committee has spent more than $3.5 million on what he called a “partisan fishing expedition with no end in sight.”

Blumenthal was willing to testify yet was served with a subpoena by armed marshals, Cummings said. He called the subpoena, issued by the panel’s chairman, Rep. Trey Gowdy, R-S.C., “abusive” and difficult to understand.

A federal judge has ordered the State Department to release batches of Clinton’s email correspondence from her time as the nation’s top diplomat every 30 days starting on June 30.

(AP)