A second top U.S. general is being probed concerning the same woman whose affair with David Petraeus forced him to resign, less than week after President Barack Obama defeated Mitt Romney and won a second term as Commander-in-Chief.
A defense official said Tuesday the U.S. commander in Afghanistan, General John Allen, is under investigation for "inappropriate" emails to Jill Kelley, a key figure in the scandal that brought down the former general and CIA chief.
The revelation represented yet another stunning turn in a widening scandal that has jolted Washington only days after the re-election of Obama, with lawmakers vowing to get to the bottom of the case, AFP reported.
The Pentagon official told reporters the FBI had uncovered a trove of 30,000 pages of correspondence between Allen and Kelley.
The senior U.S. defense official, speaking on condition of anonymity, told reporters traveling with Defense Secretary Leon Panetta there was a "distinct possibility" the Allen emails were connected to the Petraeus investigation.
"It's far too early to speculate on what the IG (inspector general) might find," the same defense official said.
"There is enough concern that we believe it was a prudent measure to take appropriate steps to direct an investigation and notify Congress," he said. "We need to see where the facts lead in this matter, before jumping to any conclusions whatsoever."
"General Allen disputes that he has engaged in any wrongdoing in this matter," he said.
Petraeus resigned on Friday, just three days after Obama was re-elected president following a heated campaign in which the CIA faced questions about its handling of a deadly attack on a US consulate in Libya.
The retired four-star general had been due to testify to Congress this week on the September 11 assault in Benghazi that killed four Americans, including US ambassador Chris Stevens and two former Navy SEALs working for the CIA.
Retired US Army colonel Steve Boylan -- a close Petraeus associate -- told AFP the affair between Petraeus and his biographer Paula Broadwell began about two months after he assumed his post at the CIA in September 2011, and thus after he retired from the U.S. Army. It ended about four months ago.
It all unraveled when 37-year-old Kelley, a Tampa socialite with close military ties who was a friend of the Petraeuses, complained to an FBI agent acquaintance that she had received threatening anonymous emails.
According to widely-reported leaks from US officials, FBI agents traced the mails back to Broadwell and, on scrutinizing her online records, found a series of sexually explicit exchanges with Petraeus confirming their affair.
Adding political intrigue to the scandal -- according to a report in Tuesday's Wall Street Journal -- the original FBI agent who was contacted by Kelley brought the matter to the attention of Republican lawmakers.
They in turn contacted the FBI, and Petraeus resigned late last week. Meanwhile, the FBI investigation itself has come under scrutiny.
According to the Wall Street Journal, supervisors pulled the whistleblower FBI agent off the case after he became "obsessed" with the matter and was caught sending Kelley shirtless photos of himself.
US lawmakers want to know why the FBI and Justice Department did not inform them or the White House about Petraeus' affair until last week, after the spy chief's sudden departure and public admission of guilt.
Nearly a dozen FBI agents on Monday searched Broadwell's North Carolina home, removing bags, boxes and pictures, local media reported. She has not been seen at her home since Petraeus resigned over the affair.
Broadwell may have revealed classified information last month by claiming at a public forum that the CIA was detaining Libyan militia members and that the practice may have triggered the September 11 attack on the US consulate. The spy agency has strongly denied holding prisoners at the CIA annex in Benghazi.
Petraeus took command of the CIA 14 months ago, retiring from the military after a glittering career that saw him lead the 101st Airborne, the US war in Iraq, its CentCom regional command and international forces in Afghanistan.
During his term, he caused a storm in Israeli-American relations by claiming that the Arab-Israeli struggle is the heart of problems in the Middle East.