Updated

MIAMI -- Author Stetson Kennedy, whose infiltration of the Ku Klux Klan helped expose its workings in the 1940s, has died. He was 94.

Historian and friend Peggy Bulger said he died Saturday. He had been in hospice care at a hospital near St. Augustine, Florida.

In the 1940s, Kennedy helped write "Superman" radio show episodes that exposed and ridiculed 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." He passed along information about the Klan to the FBI, the IRS and other authorities.

Bulger once said that Kennedy's work was one of the strongest blows against the Klan.