60 Minutes Correspondent Lesley Stahl reports the FBI believes it has "solid" evidence that the suspected mole supplied Israel with classified materials that include secret White House policy deliberations on Iran.
At the heart of the investigation are two people who work at The American Israel Public Affairs Committee (AIPAC), a powerful pro-Israel lobby in Washington.
The FBI investigation, headed up by Dave Szady, has involved wiretaps, undercover surveillance and photography that CBS News was told document the passing of classified information from the mole, to the men at AIPAC, and on to the Israelis.
CBS sources say that last year the suspected spy, described as a trusted analyst at the Pentagon, turned over a presidential directive on U.S. policy toward Iran while it was, "in the draft phase when U.S. policy-makers were still debating the policy."
This put the Israelis, according to one source, "inside the decision-making loop" so they could "try to influence the outcome."
The case raises another concern among investigators: Did Israel also use the analyst to try to influence U.S. policy on the war in Iraq?
With ties to top Pentagon officials Paul Wolfowitz and Douglas Feith, the analyst was assigned to a unit within the Defense Department tasked with helping develop the Pentagon's Iraq policy.
Defense Secretary Donald Rumsfeld has been made aware of the case. The government notified AIPAC today that it wants information about the two employees and their contacts with a person at the Pentagon.
AIPAC told CBS News it is cooperating with the government and has hired outside counsel. It denies any wrongdoing by the organization or any of its employees.
An Israeli spokesman said, "We categorically deny these allegations. They are completely false and outrageous." The suspected spy has not returned repeated phone calls from CBS News.