Washington — A close aide to Hillary Rodham Clinton testified Friday before the House committee investigating the deadly attacks in Benghazi, Libya.

Huma Abedin, a longtime confidante and staffer to Clinton, was meeting with investigators behind closed doors. Clinton herself is scheduled to appear before the Benghazi panel next Thursday in a widely anticipated public hearing.

The Benghazi panel is under intense scrutiny after two House Republicans have described the GOP-led committee as partisan and aimed at hurting Clinton's presidential bid, a characterization the panel's chairman rejects.

Abedin is vice chairwoman of Clinton's campaign and was a top State Department aide when Clinton served as secretary of state. She also worked in Clinton's Senate office.

Abedin's testimony was expected to focus on events leading up to the September 2012 Benghazi attacks, as well as the attacks themselves and their aftermath. Four Americans, including the U.S. ambassador to Libya, Chris Stevens, were killed.

An official who was not authorized to speak about the proceedings and spoke on condition of anonymity said Abedin would likely not be questioned about her employment status at the State Department or her work for the Clinton family foundation or a consulting firm with ties to former President Bill Clinton.

Congressional Republicans have said Abedin may have skirted ethics guidelines in her 2012 work as a special adviser for Hillary Clinton while she also worked for Teneo Holdings, a consulting firm co-founded by Douglas Band, a former aide to President Clinton. Abedin also reportedly worked during that period for the Clinton Foundation, a global charity that works with businesses, governments, non-governmental organizations and individuals.

The Benghazi panel interviewed two other top Clinton aides, Cheryl Mills and Jake Sullivan, last month.

Nick Merrill, a spokesman for Clinton's campaign, said it remains unclear why the committee is focused on Abedin, "given her lack of knowledge about the events surrounding Benghazi."

Merrill called the focus on Abedin "additional evidence that the actual attack in Benghazi, and its lessons about how we might better protect diplomats serving in dangerous places, are the last things on the committee's mind."