FBI agents have searched the home of Paula Broadwell, the woman at the centre of the scandal involving the former CIA Director David Petraeus, after it came to light the two were having an extra marital affair.

Petraeus resigned on Friday in light of the affair, following a tip off to the FBI from Jill Kelley, a long-time friend of the Petraeus family, who complained that Broadwell had sent her threatening emails, warning her to stay away from Petraeus.

Meanwhile, a senior defence official has said under condition of anonymity that General John Allen, the top U.S. commander in Afghanistan, is also under investigation for alleged inappropriate communication involving up to 30,000 pages of communication mostly emails,with Kelley, the very same woman who sparked the investigation into Broadwell and Petraeus.

It is still unknown if the documents reveal the disclosure of classified information. As the investigation will only look at "innappropriate communications." But a U.S. defence official , has said that Allen has denied any wrongdoing and that Panetta had opted to keep him in his job while the matter was under review.

Written and presented by Ann Salter