Holly Petraeus, General David Petraeus and Vice President Joe Biden at David Petraeus’ swearing-in as CIA director last year (Getty Images)

The deep dive into four-star general-turned-CIA director David Petraeus’ private life and fall from grace continues, as more and more reports emerge about his relationship with his biographer Paula Broadwell. For instance, it turns out that the FBI has known about Petraeus’ affair for months and one agent even told Rep. Eric Cantor last month.

The FBI got involved when Broadwell, who reportedly admitted to agents that she had an affair with Petraeus, allegedly sent “harassing” emails to another woman along the lines of “I know what you did,” “back off” and “stay away from my guy.” The other woman has now been identified as a Tampa, Florida socialite and unpaid volunteer to the military Jill Kelley. Kelly released a statement (and hired a lawyer), “We and our family have been friends with Gen. Petraeus and his family for over five years. We respect his and his family’s privacy and want the same for us and our three children.”

According to ABC News, “A close friend of Petraeus said Kelley and her husband, who are both civilians but supporters of the military community, befriended the Petraeus’ when the general was stationed in Florida… The Kelleys spent Christmases in group settings with the Petraeus’ and visited them in Washington D.C., where Jill’s sister and her son live. ‘It is very clear there was nothing going on other than friendship’ between Kelley and Petraeus, the close friend told ABC News.”

Still, Broadwell apparently believed something more might have been afoot. From the NY Times:

The involvement of the F.B.I., according to government officials, began when Ms. Kelley, alarmed by about half a dozen anonymous e-mails accusing her of inappropriate flirtatious behavior with Mr. Petraeus, complained to an F.B.I. agent who is also a personal friend. That agent, who has not been identified, helped get a preliminary inquiry started. Agents working with federal prosecutors in a local United States attorney’s office began trying to figure out whether the e-mails constituted criminal cyber-stalking.

Because the sender’s account had been registered anonymously, investigators had to use forensic techniques — including a check of what other e-mail accounts had been accessed from the same computer address — to identify who was writing the e-mails.

Eventually they identified Ms. Broadwell as a prime suspect and obtained access to her regular e-mail account. In its in-box, they discovered intimate and sexually explicit e-mails from another account that also was not immediately identifiable. Investigators eventually ascertained that it belonged to Mr. Petraeus and studied the possibility that someone had hacked into Mr. Petraeus’s account or was posing as him to send the explicit messages.

Eventually they determined that Mr. Petraeus had indeed sent the messages to Ms. Broadwell and concluded that the two had had an affair. Then they turned their scrutiny on him, examining whether he knew about or was involved in sending the harassing e-mails to Ms. Kelley.

Officials say that the FBI interviewed Broadwell in late October and in early November, and she voluntarily gave them her computer, where they found classified documents. In the meantime, the FBI agent friendly with Kelley thought that nothing was being done and contacted Cantor’s office. Cantor then passed the information along to FBI Director Robert Mueller, but “Hurricane Sandy delayed the message to Mueller until Oct. 31.”

Unsurprisingly, Petraeus’ wife of 38 years, Holly, is not very happy. Family friend and former spokesman for David Petraeus Steve Boylan told Good Morning, America, “Well, as you can imagine, she’s not exactly pleased right now.” Boylan, who retired from the army as a colonel, said he spoke to the cheating husband who “said that, ‘Furious would be an understatement.’ And I think anyone that’s been put in that situation would probably agree. He deeply hurt the family.”

Lawmakers from both sides of the aisle want an investigation into the investigation. Recently, Broadwell also disclosed sensitive information about the attack on the U.S. consulate in Beghazi, Libya. Here are some details on how and when the FBI can access your email.