‘Hundreds’ Gave Data to KGB, Book Says : Espionage: Author says FBI agents across country are investigating charges by ex-Soviet security employee. Agency calls report ‘exaggerated.’

FBI agents across the country are investigating allegations by a former KGB employee that “many hundreds of Americans and possibly more than 1,000” provided the former Soviet intelligence agency with information in recent years, according to a new book on the FBI.

The bureau already has “confronted some of the alleged spies, including military men who had top secret information and officials of other government agencies,” author Ronald Kessler wrote in his book, “The FBI: Inside the World’s Most Powerful Law Enforcement Agency.”

“One confessed, and others refused to talk until they saw their lawyers,” according to advance proofs of the book made available to reporters Tuesday. Kessler, in the interview, said that no prosecutions have yet resulted from the ex-KGB employee’s allegations.

Although some FBI sources characterized Kessler’s description as “exaggerated”--particularly his reference to estimates that more than 1,000 Americans are involved, none disputed that the FBI had obtained information from a former KGB employee that sparked a number of investigations.

These sources said that they did not know of any official who confessed after being confronted with the ex-KGB employee’s allegation.

“Based on information that continues to be received in the aftermath of the Cold War, the FBI, pursuant to its foreign counterintelligence responsibilities, has opened a number of cases related to the activities of the former KGB and its successor agency,” the FBI said in an official statement.

“The process of thoroughly analyzing and evaluating that kind of information continues in an effort to determine its value and any appropriate investigative direction,” the statement said.

The accuracy of the information provided to Kessler, as well as the agency’s response Tuesday, is difficult to determine. Reporting on intelligence matters can be tricky, both for daily journalists and book authors, because the agencies involved can provide misleading information as part of counterintelligence operations.

Kessler, who has written five earlier books on intelligence and counterspies, said in an interview that the ex-KGB source was a low-level employee with access to the agency’s files and that the FBI obtained the information last spring. The book does not mention the quality or importance of the information allegedly passed to the KGB, other than to note that some of the Americans had access to top secret material.

“So specific was the information that the FBI was quickly able to establish the source’s credibility,” Kessler wrote.

“By the summer of 1993, the FBI had mobilized agents in most major cities to pursue the cases,” he said. “A top secret meeting was called at Quantico (the Virginia site of the FBI’s training academy) to plot strategy.”

The allegation came a little more than a year after the FBI, reacting to the end of the Cold War, transferred 300 foreign counterintelligence agents to squads assigned to investigate urban gangs and to related criminal work. The FBI intelligence division has been reduced to about 2,000 agents, drawn from a total agent force of more than 10,000.

Kessler said that the allegation provided the FBI’s intelligence division with “enough to keep it busy into the next century.”

Wayne Gilbert, who retired two weeks ago as assistant director in charge of the FBI’s intelligence division, said that the information as presented by Kessler “is certainly not accurate.”

But Gilbert, now director of corporate security for Johnson & Johnson in Brunswick, N.J., declined to “qualify how much is accurate or inaccurate.”

“There’s a substantial amount of work (going on in the intelligence division), and certainly a lot of it was generated by the KGB,” Gilbert said. “We do have a large number of espionage cases” under way, he said.

Kessler was given extraordinary access to the FBI by former Director William S. Sessions.

During his research, Kessler uncovered some of the allegations of abuse of office by Sessions that led to his being fired by President Clinton.