And as we come on the air, new details are pouring in about the man inrge of so many of the nation's secrets, general david petraeus, forced to resign. And what about the woman at the center of his... See More
And as we come on the air, new details are pouring in about the man inrge of so many of the nation's secrets, general david petraeus, forced to resign. And what about the woman at the center of his story? Tonight, new questions, as well, about what was really going on and when and the avalanche of e-mails now beginning to emerge. Abc's martha raddatz reports in now. Martha? Reporter: Diane, an official tells abc news tonight,s the fbi discovered hundreds, if not thousands, of e-mails between david petraeus and paula broadwell on her computer, an affair that petraeus is claiming did not begin until he left the army. A friend close to petraeus says the general was "shocked and surprised" to learn broadwell had been sending anonymous threatening e-mails to jill kelley, the petraeus family friend who was so alarmed by the e-mails, she called the fbi. Those friends also tell us the general's wife, holly petraeus, is furious with her husband. You see her here at his confirmation hearings back in august of 2011, broadwell sitting just a few seats away. Petraeus insists they weren't having an affair then, which leads us to the first big question -- when did the affair begin? Petraeus' friends claim it started around november 2011, two months after he took over the cia, an important point, since he could be tried under military law for adultery. It didn't begin when he was in the army. Reporter: But many who know the general suspect it began months earlier in afghanistan. It was september 2010 that broadwell made her first of six visits to petraeus in the warzone after being granted extraordinary access to write the book about him. When I was in kabul, we would do a lot of interviews on runs. For him, I think it was a good distraction from the war. Reporter: Question two -- when did the fbi get involved? It was around may or june that the fbi was tracing those threatening e-mails sense to petraeus' friend jill kelley. Broadwell turned over her computer to the fbi, where they found a trove of explicit e-mails between petraeus and broadwell. The fbi does not believe petraeus gave any classified information to broadwell, though there was some found on her computer. And tonight, there are calls from capitol hill to find out why it was the white house was not informed about this investigat diane, until five months after it began.
This transcript has been automatically generated and may not be 100% accurate.