A judge once ruled it “unintelligible at any speed”.
AND!...The almost universal belief in 1963-1964 that the Kingsmen had slipped something obscene into a song being played on the radio where minors could hear it every bloody day actually led to an investigation of the record by the FBI! The investigation lasted through 1965 but as none of the agency’s experts could figure out what the heck Ely was actually singing, they had to leave the record alone.More...The FBI investigated The Kingsmen's 1963 song "Louie Louie" for alleged obscene lyrics, following complaints from parents and others who believed the song contained inappropriate content. The investigation, which began in early 1964, was sparked by widespread rumors and misinterpretations of the song’s largely unintelligible lyrics, sung by Jack Ely. The FBI's probe, part of their efforts to address obscenity under federal laws like the Interstate Transportation of Obscene Material statute, lasted from February to May 1964, with some activity continuing into 1965. Agents analyzed the song at various speeds and interviewed band members, the song’s original writer Richard Berry, and others, but never contacted Ely himself. Despite a 455-page report, the FBI concluded the lyrics were "unintelligible at any speed" and found no definitive evidence of obscenity, closing the case without charges. The controversy was fueled by circulated fake lyrics and cultural anxieties about rock 'n' roll’s influence on youth, though the only actual obscenity was an accidental "f**k" muttered by drummer Lynn Easton at 56 seconds after dropping a drumstick, which went unnoticed by investigators.
There’s a book about the history of”Louie, Louie” and the FBI’s investigation of it. The correct lyrics were published by the WSJ in its middle human interest column.