For more than two years, the FBI has been investigating whether classified intelligence has been passed to Israel by the American Israel Political Action Committee, an influential U.S. lobbying group, in a probe that extends beyond the case of Pentagon employee Lawrence A. Franklin, according to senior U.S. officials and other sources.

The counterintelligence probe, which is different from a criminal investigation, focuses on a possible transfer of intelligence more extensive than whether Franklin passed on a draft presidential directive on U.S. policy toward Iran, the sources said. The FBI is examining whether highly classified material from the National Security Agency, which conducts electronic intercepts of communications, was also forwarded to Israel, they said.

Israel said the characterization of the probe is speculative. "We are aware of all the speculation, but that is all it is. We have not heard anything official, and U.S.-Israeli relations remain as strong as ever and, as far as we are concerned, it's business as usual," said David Siegel, spokesman of the Israeli Embassy here.

AIPAC has forcefully denied that any of its personnel received classified information.

National security adviser Condoleezza Rice and her deputy, Stephen J. Hadley, were apprised of the FBI counterintelligence investigation of AIPAC as a possible conduit for information to Israel more than two years ago, a senior U.S. official said late yesterday. That official and other sources would discuss the investigation only on the condition of anonymity because it involves classified information and is highly sensitive.

The investigation of Franklin is coincidental to the broader FBI counterintelligence probe, which was already long underway when Franklin came to the attention of investigators, U.S. officials and sources said. Franklin, a career analyst at the Defense Intelligence Agency who specializes in Iran, is suspected of passing the proposed directive on Iran to AIPAC, officials said, which may have forwarded it to Israel. According to friends and colleagues, Franklin spent time in Israel, including during duty in the U.S. Air Force Reserve, in which he served as a specialist in foreign political-military affairs. Franklin now works for Douglas J. Feith, undersecretary of defense for policy.

Reports on the investigation have baffled foreign policy analysts and U.S. officials because the Bush administration and the government of Prime Minister Ariel Sharon already cooperate on intelligence matters and share policy views. Despite some rocky moments, the relationship has been among the United States' closest in both policy and intelligence sharing since Israel was founded almost six decades ago.

AIPAC has been one of the most active advocates for Israeli interests in the United States and a central element in fostering that relationship. Its lobbyists maintain close relations with officials at the highest levels of both governments.

Among the many unanswered questions in the case, sources familiar with it said, is whether a U.S. official with access to the intelligence volunteered it, or whether allies of Israel in the United States sought intelligence to pass on to Israel.

In the Franklin probe, a law enforcement official said the government does not expect to bring charges against anyone this week or next. U.S. Attorney Paul McNulty in Northern Virginia, whose office is handling the case, is continuing to examine the evidence gathered by the FBI, the official said. Officials have said Franklin is cooperating with the authorities. Attempts to reach him at his office and home over several days have been unsuccessful.

The FBI's counterintelligence investigation was underway for some time before the Franklin case was brought to the U.S. attorney's office, which happened fairly recently, according to a source knowledgeable about the case.

FBI counterintelligence investigations often involve wiretapping and other forms of surveillance and can last years. They differ from criminal investigations because the goal is to obtain information about foreign agents or terrorists without necessarily seeking criminal charges. Counterintelligence agents previously were limited in sharing information with the FBI's criminal division, but they now do so more routinely as a result of a decision two years ago by a secret intelligence court and the 2001 passage of the USA Patriot Act.

Lawyer Abbe Lowell, who is representing several AIPAC employees, including AIPAC's policy director, Steve Rosen, declined to comment on a report in the Jerusalem Post that the FBI had copied Rosen's computer hard drive. He also would not say whether AIPAC officials have been told that they are subjects or targets of the FBI probe.

But a source close to AIPAC said that the FBI has interviewed numerous AIPAC officials in recent days, among them Rosen and Middle East analyst Keith Weissman, who the source said were interviewed on Friday. They and other AIPAC officials are cooperating in the probe and have turned over materials sought by the bureau, the source said.

AIPAC's attorney, Nathan Lewin, did not return calls seeking comment yesterday. Josh Bloc, a spokesman for the group, referred to a statement AIPAC issued Friday, when the first allegations surfaced in the news media about an FBI investigation involving Franklin and AIPAC.

"AIPAC has learned that the government is investigating an employee of the Department of Defense for possible violations in handling confidential information," the statement said. "Any allegation of criminal conduct by AIPAC or our employees is false and baseless. Neither AIPAC nor any of its employees has violated any laws or rules, nor has AIPAC or its employees ever received information they believed was secret or classified."

Staff writer Thomas E. Ricks contributed to this report.

Commentary:
Another day, another intelligence leak.