A senior U.S. military official says the author who had an affair with David Petraeus sent  harassing emails to a woman who was the State Department’s liaison to the  military’s Joint Special Operations Command.

The official says 37-year-old Jill Kelley in Tampa, Fla., received the  emails from Petraeus biographer Paula Broadwell that triggered an FBI  investigation.

The official was not authorized to discuss the case publicly and spoke on  the condition of anonymity.

Another person who knows Kelley and Petraeus confirmed their friendship and  said she saw him often.

Petraeus quit as CIA director last week after acknowledging an extramarital  relationship with a woman — later identified as Broadwell.

The FBI probe began several months ago with a complaint against Broadwell.  That investigation led to Broadwell’s email account, which uncovered the  relationship with Petraeus.