In July 2004, a Defense Department analyst and a senior official from an influential pro-Israel lobbying group met at the Pentagon City mall in Arlington. Amid the stores and shoppers, the analyst warned that Iranian agents were planning attacks against American soldiers and Israeli agents in Iraq, sources familiar with the meeting said.

Alarmed, the American Israel Public Affairs Committee official, Keith Weissman, left the mall and went to the office of colleague Steve Rosen. The two men then relayed the information to the Israeli Embassy in Washington and a reporter for The Washington Post.

What the AIPAC officials did not know, the sources said, was that the FBI was listening in -- to both the meeting and their subsequent phone calls -- and that the Pentagon analyst, Lawrence Franklin, was cooperating in an investigation of whether classified U.S. information was being passed on to the government of Israel.

That meeting and those phone calls are a focus of a criminal case prosecutors are building against Rosen and Weissman, who recently left their jobs at AIPAC, according to multiple sources familiar with the investigation. Franklin has already been charged, and a looming court battle will probably turn on whether he and others were illegally passing government secrets or were merely conduits of the type of policy-related information that is frequently bandied about in official Washington.

The meeting at the mall is not mentioned in the publicly filed charges, and new details are emerging about a series of FBI-monitored meetings between Franklin and the former AIPAC officials dating back to early 2003. But many questions remain unanswered, such as whether the information Franklin allegedly passed along at those sessions was classified, and if it was, whether Rosen and Weissman knew it was classified, and whether any damage was done to U.S. national security.

Rosen and Weissman have been notified that prosecutors are preparing to charge them with disclosing classified information, sources familiar with the investigation said.

Federal prosecutors and the FBI would not comment, nor would John Nassikas, an attorney for Weissman. An attorney for Rosen, Abbe D. Lowell, said that "when all the facts come out, the government will have more to explain about its conduct than Steve Rosen will about his." Earlier, he said that Rosen "never solicited, received or passed on any classified documents" from Franklin. A spokesman for the Israeli Embassy did not return phone calls. A Post spokesman confirmed that the reporter, Glenn Kessler, recently declined a Justice Department request to be interviewed. Kessler would not comment yesterday.

Franklin's attorney, Plato Cacheris, confirmed that Franklin briefly cooperated with investigators in the summer of 2004, during the time of the meeting at the mall. Cacheris said that Franklin, whom he described as a "loyal and patriotic American citizen," is no longer cooperating and plans to go to trial.

Last month, Franklin was charged in a criminal complaint in U.S. District Court in Alexandria with disclosing classified information related to potential attacks on U.S. forces in Iraq. Court documents did not reveal who received the information, but federal law enforcement sources have said that Franklin disclosed it to Rosen and Weissman at an Arlington restaurant in June 2003.

The sources also said the attacks would have been carried out by Iran. At the time, the U.S. government was concerned about Iranian activities in Iraq after the U.S.-led invasion that year. Federal prosecutors in Alexandria have notified Franklin that he would be indicted by a grand jury, and Franklin has been told to appear in federal court June 13. Sources familiar with the case said the court appearance relates to a sealed indictment.

Franklin was also charged again last week in federal court in West Virginia with possessing 83 classified documents dating back three decades. They were found at his West Virginia home.

The contacts between Franklin, an Iran specialist, and former AIPAC policy director Rosen and senior analyst Weissman extend back before the June 2003 lunch. In February 2003, the three met at the Ritz-Carlton Pentagon City hotel in Arlington in a session that they only learned later was under FBI surveillance, sources said. It is unclear whether agents were following Franklin or the AIPAC officials.

After the 2004 meeting, sources said that Rosen and Weissman called Kessler and relayed what Franklin had told Weissman about possible Iranian attacks against Americans and Israelis in Iraq. Law enforcement sources said that Kessler, who did not write an article based on the phone conversation, is not a target of the investigation.