Today, Congress embarks upon a week of hearings and in order to determine what actually occurred in the September 11 attacks on Benghazi.

However, it appears that two of the most important and knowledgeable sources will not be testifying.

Former CIA director David Petraeus, who resigned on Friday when an FBI investigation uncovered evidence of his extramarital affair, will no longer appear before lawmakers. His interim replacement, Mike Morrel, will testify on the CIA's behalf.

Secretary of State Hillary Clinton, who has come under serious flak for allegedly ignoring requests to beef up security at the Benghazi consulate prior to its attack, will not testify as well. "She was asked to appear at House Foreign Affairs next week, and we have written back to the Chairman to say that she’ll be on travel next week," State Department spokesperson Victoria Nuland told reporters on Friday. Under Secretary Patrick Kennedy and Assistant Secretary Eric Boswell, two top ranking officials at State, will appear at the hearings in her stead.

Clinton will be in Australia to attend the annual Australia-United States Ministerial (AUSMIN) consultations. Rumors have circulated — which both sides have rebuffed — that the United States is concerned with possible budget cuts to the Australian military. The U.S. sees Australia as a strong counterweight to the growing military powers in the Pacific, including China.

Both Petraeus and Clinton would have testified in closed sessions.

While the replacements chosen to appear before congress are very high-level experts, some lawmakers and observers are not pleased that neither Clinton nor Petraeus will show in what some have deemed an extensive cover up by the Obama administration.

Representative Ileana Ros-Lehtinen, Chairman of the House Foreign Affairs Committee, told Clinton it was "disappointing that we have yet to receive any response from your Department and that we are receiving more information from the press than from the Administration," in a letter last week.

And conservative media mogul Rupert Murdoch tweeted the following: