Threatening e-mails said to have brought down CIA chief

WASHINGTON (AFP) - The plot surrounding the resignation of CIA chief David Petraeus over an extramarital affair thickened on Sunday amid reports that his alleged lover had sent emails to a second woman she viewed as a threat to her love interest.

The affair came to light as the Federal Bureau of Investigation (FBI) was investigating whether a computer used by General Petraeus - a married father of two - had been compromised, the New York Times and other US media reported, citing government officials.

NBC News and other media reported that the FBI was focusing on Ms Paula Broadwell, co-author of a favourable biography of Gen Petraeus, for possible improper access to classified information.

Unnamed officials told the Times that Gen Petraeus's lover was Ms Broadwell, a former Army major who spent long periods interviewing him for her book.