An official familiar with a House committee’s investigation of the Benghazi, Libya attack says the panel has subpoenaed a longtime Hillary Rodham Clinton confidant.

This official tells The Associated Press the subpoena was issued to Sidney Blumenthal. The official declined to be publicly identified because of the ongoing probe of a September 2012 attack at the U.S. diplomatic post at Benghazi that killed U.S. Ambassador Christopher Stevens and three others.

The official says the House panel has “a number of questions” for Blumenthal, including whether he had any business arrangements that led him to frequently email Clinton about Libya when she was secretary of state.

Rep. Elijah Cummings of Maryland, ranking Democrat on the panel, is assailing the committee’s decision to have the U.S. Marshals Service deliver the subpoena to Blumenthal’s home, calling that “heavy-handed.”

(AP)