(Fox News) CIA Director David Petraeus resigned Friday after admitting to an extramarital affair — an affair with his biographer that was revealed over the course of an FBI investigation, Fox News has learned.

The FBI had been investigating an unrelated and much broader case before stumbling on the affair. Fox News has learned that during the course of this investigation, the name of biographer Paula Broadwell came up. The FBI followed that lead and in doing so, uncovered his affair with her. The FBI for some time was concerned that perhaps Petraeus was some sort of victim, but there has been no evidence discovered to back up such concerns.

Broadwell co-wrote Petraeus’ biography, “All In.”


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