Washington CNN  — 

The chairman of the House committee investigating Benghazi said Tuesday revelations that former Secretary of State Hillary Clinton used multiple personal email accounts to conduct government business are troubling.

House Select Committee on Benghazi Chairman Trey Gowdy said his committee knew that Clinton used personal email to conduct government business last summer, but only recently learned that she did not also use an official government account.

READ: Clinton had no official State Dept. email address

“She used only private email accounts and she had more than one private email account,” Gowdy said.

A Clinton aide says Gowdy is wrong, and that she did not use multiple email accounts.

The committee, which is investigating the attack on the U.S. consulate in Benghazi that killed four Americans, plans to request the emails from Clinton and the email service providers she used, Gowdy said. He added that Clinton’s use of personal email accounts makes it harder for the committee to gather the facts.

“You do not need a law degree to have an understanding of how troubling this is,” he said.

Gowdy said the fact that other congressional investigations of Benghazi never uncovered Clinton’s email use proves that further inquiry is needed.

He said he does not plan to publicly release Clinton emails.

The New York Times first reported the news Tuesday and Gowdy said his committee was not the source of the story.