Washington, DC (CNN)A member of the House select committee investigating the January 6 attack told CNN Saturday many of the more than 200 witnesses they have interviewed are former officials from the Trump administration who came forward voluntarily.

Rep. Zoe Lofgren, a California Democrat, said some others have also volunteered testimony, but needed a subpoena for "cover." Lofgren remained relatively tight-lipped, however, and wouldn't say whether they were members of the Trump White House, the Trump campaign, or former Vice President Mike Pence's staff when pressed by CNN's Jim Acosta.