A gravedigger who helped expose an alleged scheme to dig up graves and resell plots at a suburban Chicago cemetery says he only spoke up after another worker warned him to keep his mouth shut or risk losing his job.

Willie Esper tells The Associated Press he told a supervisor at Burr Oak Cemetery in Alsip that he'd spotted bones while practicing digging graves but that he wasn't going to say any more.

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But when the other worker asked how he was going to feed his young son without a job, he says he got mad and started talking within earshot of a worker he knew would spread the word.

Esper's version of events is fairly consistent with what's contained in a court document in which prosecutors outline the investigation. Four people are charged in the case.