VATICAN CITY - Pope Francis has a message for church benefactors: The church doesn't want your money if it comes from exploited workers.

Francis railed against employers who mistreat and underpay their workers during his general audience Wednesday. It's a theme the Jesuit pope has frequently emphasized, denouncing how the wealthy exploit the poor and working class for their own profit, often subjecting workers to slave-like conditions.

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Francis told the crowd in a sunny St. Peter's Square that when he thinks about church benefactors who offer donations that are "fruit of the blood" of exploited workers, he tells them: "Please, take your checks back and burn them."

He added: "The people of God and the church don't need dirty money. They need hearts that are open to the mercy of God."