The extramarital affair involving former CIA director David Petraeus surfaced once more after his friend, Jill Kelley, revealed recently that Petraeus' mistress threatened to blackmail her.

Kelley was "terrified" in the summer of 2012 when biographer Paula Broadwell sent her emails that had "blackmail, extortion, [and] threats" regarding her friendship with Petraus, she told The Daily Beast in her first interview since the scandal surfaced nearly three months ago.

At the time, the emails were sent anonymously and Kelley only learned much later that they were sent from Broadwell.

The Florida socialite said her husband, Scott, was the first to see the messages. He opened the note on his phone under the Yahoo account the couple shares right before he was about to board a plane. He told his wife about the messages and when she first read it herself, she said the writer was so ambiguous that "I didn't even know it was a female."

A source close to Jill said the tone of the messages grew harsh and threatening without being explicit, but Jill noted that the anonymous emails did not warn her to stay away from Petraeus, contrary to what reports suggested.

At the time of the affair and the threatening emails, Jill had no idea who Broadwell was - "I never met Paula in my life" - and did not even know she was writing a biography about Petraeus.

She did not comment on Broadwell's motive behind the threatening messages.

Jill served as a social liaison to MacDill Air Force Base in Tampa, Fla., where the military's Central Command and Special Operations Command is located, according to RGJ.com. When she reported the threatening messages to authorities an investigation into the matter began, which eventually led FBI agents to find out that the then-CIA director was having an affair with his biographer.

Petraeus was asked to resign in November 2012 and the extramarital scandal became global news focusing on those who knew about it, who were involved and whether government information was compromised. Petraeus even topped Barbara Walters' list of the "10 Most Fascinating People" of 2012.

Jill was brought into the mix because of her family's close friendship with Petraeus' and reports suggested that she engaged in "inappropriate communications" with Gen. John Allen, the U.S. commander in Afghanistan. She denied those allegations and called rumors of 30,000 emails sent between them "outrageous."

Tags: jill kelley paula broadwell david petraues