MIAMI – Author and folklorist Stetson Kennedy, who infiltrated the Ku Klux Klan six decades ago and exposed its secrets to authorities and the public but was also criticized for possibly exaggerating his exploits, died Saturday. He was 94.

In the 1940s, Kennedy used the “Superman” radio show to expose and ridicule the Klan’s rituals. In the 1950s he wrote “I Rode with the Ku Klux Klan,” which was later renamed “The Klan Unmasked,” and “The Jim Crow Guide.”

“Exposing their folklore — all their secret handshakes, passwords and how silly they were, dressing up in white sheets” was one of the strongest blows delivered to the Klan, Peggy Bulger, director of the American Folklife Center at the Library of Congress, said in 2007.

Kennedy began his crusades against what he called “homegrown racial terrorists” during World War II after he was deemed unworthy for military service because of a back injury. He served as director of fact-finding for the southeastern office of the Anti-Defamation League and served as director of the Anti-Nazi League of New York.

“All my friends were in service and they were being shot at in a big way. They were fighting racism whether they knew it or not,” Kennedy said. “At least I could see if I could do something about the racist terrorists in our backyard.”

Using evidence salvaged from the Grand Dragon’s waste basket, he enabled the Internal Revenue Service to press for collection of an outstanding $685,000 tax lien from the Klan in 1944 and he helped draft the brief used by the state of Georgia to revoke the Klan’s national corporate charter in 1947.

Kennedy infiltrated the Klan by using the name of a deceased uncle who had been a member as a way to gain trust and membership. But the Klan did not know that Kennedy was giving its secrets to the outside world, including the Georgia Bureau of Investigation, the Anti-Defamation League and Drew Pearson, a columnist for The Washington Post.

When Kennedy learned of plans for the Klan to take action, he would make sure it was broadcast, thwarting them.

“They were afraid to do anything. They knew that somebody was on the inside. They had first-class detectives looking, and I was trying hard not to be caught,” Kennedy said.

In the late 1940s, while working as a consultant to the Superman radio show, Kennedy provided information to producers on information about the Klan from their rituals to secret code words.

He testified before a federal grand jury in Miami about the Klan chain of command in the 1951 bombing death of Florida NAACP leader Harry Moore and bombings aimed at black, Catholic and Jewish centers in Miami.

He presented evidence in federal court in Washington, D.C., of Klan bombings and other violence aimed at preventing blacks from voting in the 1944 and 1946 elections.

Late in life, Kennedy was miffed at allegations that some of his writings about the Klan were fabricated or exaggerated. Stephen J. Dubner and Steven D. Levitt, co-authors of the book “Freakonomics,” alleged that Kennedy misrepresented portions of “I Rode With the Ku Klux Klan,” as did critic Ben Green, a Tallahassee writer about the civil rights era.

Kennedy acknowledged that some of the material came from another man who also infiltrated the Klan, but did not want his name used. He said he intermingled his experiences and that of the other man in a narrative to make them more compelling.