The earliest instance of to know where the bodies are buried that I have found is from the Daily News (New York, N.Y.) of Sunday 25th January 1931, which published Hollywood Blackmail Spectre Looms, an article by the American reporter and author Florabel Muir (1889-1970) about“the blackmail racket”in the film industry:
Eddie Doherty, whose accurate reporting more than once gave Hollywood chills and fever in other days, told me when I first came out here:
“These people don’t know you yet. Give ’em time and they will. They’ll find out that you shoot square. Then they’ll start telling you things, things you can’t believe about other people. The funny part is that they will all be true, the things they tell you, hoping you’ll publish them. All of Hollywood is a great spy system with every one trying to get something on the other fellow.”
He was right. You see some obvious incompetent hoisted into a job away over his head and immediately the whisper goes round, “he knows where the bodies are buried.”