Defence Secretary Leon Panetta revealed that the Pentagon had begun an internal investigation into thousands of pages of emails from General John Allen to a second woman involved in the Petraeus case.
Gen Allen succeeded Gen Petraeus as the top American commander in Afghanistan in July 2011, and his nomination to become the next commander of the US European Command and the commander of Nato forces in Europe has been put on hold.
In a White House statement, National Security spokesman Tommy Vietor said President Barack Obama has delayed Gen Allen’s nomination at Mr Panetta’s request. Mr Obama, the statement said, “remains focused on fully supporting our extraordinary troops and coalition partners in Afghanistan, who Gen Allen continues to lead as he has so ably done for over a year”.
Meanwhile, FBI agents prepared a timeline of the Petraeus affair and searched the home of Paula Broadwell, the 40-year-old biographer with whom 60-year-old Gen Petraeus had an affair that led to his abrupt resignation last week.
The resignation and his acknowledgement of an affair stunned Washington because of the former general’s highly disciplined and well-praised career, which had led some to speculate of a possible a run for the White House in his future. The retired army general, who is married, headed US military operations in Iraq and Afghanistan before taking charge of the CIA.
It was Ms Broadwell’s alleged threatening emails to Jill Kelley, a 37-year-old Florida woman who is a Petraeus family friend, that led to the FBI’s discovery of communications between Ms Broadwell, who is also married, and Gen Petraeus indicating they were having an affair.
A Pentagon official said 20,000 to 30,000 pages of emails and other documents from Gen Allen’s communications with Ms Kelley between 2010 and 2012 are under review. He would not say whether they involved sexual matters or whether they are thought to include unauthorised disclosures of classified information. He said he did not know whether Gen Petraeus was mentioned in the emails.
Gen Allen has denied any wrongdoing.
The new details in the case brought expressions of amazement in Congress, already in an uproar over the Petraeus affair.
Peter King, chairman of the House Homeland Security Committee, called the case “a Greek tragedy”.
Mr King said: “This has the elements in some ways of a Hollywood movie or a trashy novel.”
Politicians have said they should have been told earlier about the affair and are asking what the FBI knew and when it notified top Obama administration officials.
The White House was not informed of the FBI investigation that involved Gen Petraeus until November 6, election day, although agents began looking at Gen Petraeus’s actions months earlier, sometime during the summer.
Senate Intelligence Committee chairwoman Dianne Feinstein said she first learned of the matter from the media late last week and confirmed it in a phone call to the then-CIA director on Friday. Mr Obama accepted Gen Petraeus’s resignation on Friday.