In what seemed to be an unusual disclosure, Attorney General Eric Holder today testified that both he and FBI Director Robert Mueller have been interviewed by FBI agents conducting the leak investigation into disclosures of the recent Al Qaeda bomb plot.

"In an abundance of caution - I'll just say this - both the director and I have been already interviewed in connection with the knowledge that we had of those matters; at least of that matter," Holder testified before the Senate Judiciary Committee.

Agents from the Washington Field Office have been investigating the leaks about the averted attack, which was first revealed by The Associated Press. The FBI is also investigating the source of the leak over who revealed that the individual at the center of the plot was a double agent working for Britain's MI-6 secret intelligence service and the CIA, along with Saudi Arabian intelligence assets.

"I can also tell you that I have been interviewed already and I can tell you that that interview was not some kind of pro forma, 'take it easy' interview. I mean, these were serious - a serious interview that was done by some serious FBI agents. The same thing happened to the director of the FBI, as well, because we were people who had knowledge of these matters and we wanted to make sure that with regard to the investigation that it began with us," Holder testified

Holder was extensively questioned by Republican senators about why he has not appointed a special counsel to oversee the leak investigations into the Al Qaeda in the Arabian Peninsula bomb plot and the disclosures about President Obama ordering cyber-attacks against Iran with the Stuxnet computer worm that appeared in an article in the New York Times by David Sanger. Last Friday Holder appointed Ron Machen, the U.S. attorney for the District of Colombia, and Rod Rosenstein to lead the criminal investigations.

Sen. Lindsey Graham, R-S.C., drew a connection of the leaks to the White House in his questioning of Attorney General Holder, citing Sanger's book on Obama's foreign policy, "Confront and Conceal."

"Mr. Sanger clearly has enjoyed great access to senior White House officials, most notably to Thomas Donilon, the national security adviser. Mr. Donilon, in effect, is the hero of the book as well as the commentator of record on events. I don't know what Mr. Donilon did, but according to this review and from my reading of excerpts of the book, somebody at the highest level of our government has been talking about programs that I think are incredibly sensitive," Graham said.

"I think they are extremely serious," Holder said about the damaging effect of the leaks but defended his appointment of the two U.S. attorney's to lead the cases.

"The two people, I have appointed to look into these matters, are first-rate prosecutors, who will do, I think, a great job. And as we look at the history of what U.S. attorneys, who have been appointed in these kinds of cases, I think we can feel a great deal of comfort," Holder said.

Graham said it was a double standard that Holder has not appointed a special counsel yet when compared to the leak investigation of CIA Officer Valerie Plame, which focused on the Bush White House.

"Vice President Biden was on TV morning, noon and night, urging the Bush administration to appoint a special counsel in the Valerie Plame case," Graham said.

"As attorney general, I am seized with the responsibility of looking at allegations, controversies and making the decision on the basis of what I think is best for a successful investigation and potential prosecution," Holder said.

In the Plame case then Attorney General John Ashcroft recused himself from the investigation when it appeared the White House may be involved. Several months after the initial investigation began then Deputy Attorney General James Comey appointed U.S. Attorney Patrick Fitzgerald as special counsel.

Under questioning from Sen. Jon Kyl, R-Ariz., Holder hinted today that he may have to recuse himself at some point.

"Could you specifically tell us whether either David Axelrod or the president or Jay Carney have a valid basis for reaching the conclusion that the case does not present a conflict of interest? Can they really say that at this point knowingly?" Kyl asked.

"Well, I would say on the basis of what I know at this early stage of the investigation, there is not a basis for a conflict determination. But it is something that we are monitoring on an ongoing basis. Director Mueller and I have both set up in place at the Justice Department and the FBI a mechanism so that we can be advised on the possibility of a conflict. And if, at some point, the people who have been given that responsibility indicate to Bob - to Director Mueller or to me that we are in a conflict situation, we will act appropriately," Holder said.

Texas Republican Sen. John Cornyn, who had called for Holder's resignation during the hearing, asked Holder if he was concerned that U.S. Attorney Ron Machen, who is heading up one of the criminal leak investigations, had made $4,600 in political donations to the Obama campaign in 2007 and 2008 before he was appointed U.S. attorney.

"Would it surprise you to know that he is a political contributor to President Obama's campaign and indeed serves as a volunteer in 'Obama for America,' and assisted in the vetting of potential vice presidential candidates?" Cornyn asked.

"I am confident that he has the ability, the capacity to investigate this case in a non-partisan, independent, thorough and aggressive way," Holder responded.

Following Holder's hearing Sen. John McCain, R-Ariz., introduced a resolution in the Senate calling for the appointment of a special counsel to investigate the string of recent national security and intelligence leaks.