MIAMI (AP) — Stetson Kennedy, who infiltrated the Ku Klux Klan six decades ago and exposed its secrets but was criticized for possibly exaggerating his exploits, died on Saturday. He was 94.

His death, in hospice care near St. Augustine, Fla., was announced on his Web site.

In the 1940s, Mr. 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.”

Peggy Bulger, the director of the American Folklife Center at the Library of Congress, was a friend of Mr. Kennedy and did her doctoral thesis on his work as a folklorist. “Exposing their folklore — all their secret handshakes, passwords and how silly they were, dressing up in white sheets” — was one of the strongest blows to the Klan, she said in a 2007 interview with The Associated Press.

Mr. 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. “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,” Mr. Kennedy said. “At least I could see if I could do something about the racist terrorists in our backyard.”