The Republican chairman of a House panel looking into the attacks on the U.S. consulate in Benghazi, Libya, wants to take depositions from the leaders of an earlier review board.

California’s Rep. Darrell Issa, head of the Oversight and Government Reform Committee, on Sunday said he would like to interview under oath former Ambassador Thomas Pickering and retired Adm. Mike Mullen, the former chairman of the Joint Chiefs of Staff. Pickering and Mullen led an investigation that examined the September attacks that killed four Americans, including an ambassador.