http://www.washingtonpost.com/wp-srv/national/longterm/watergate/fbi.htm
(SNIP)
In his article, Mann said three FBI officials confronted Gray and protested what they saw as the White House's interference with the bureau's Watergate probe. They were W. Mark Felt, FBI deputy associate director (and known by reporters as someone willing to take their calls); Charles W. Bates, the assistant director in charge of the FBI's general investigative division; and Robert Kunkel, the special agent in charge of the Washington, D.C., field office. Mann identified all three as Deep Throat suspects.
I feel so old, how could anyone not know who Deep Throat was.