A federal law enforcement official said the FBI obtained a court warrant before viewing the contents of Broadwell's Gmail account. The FBI did not notify Broadwell beforehand, an omission that is not unusual, said the official, who spoke on condition of anonymity because the source was not authorized to speak on the record about the investigation.
The FBI also found emails between Kelley and Allen that were turned over to the Defense Department for investigation. Obama has put on hold Allen's nomination to become the next commander of U.S. European Command as well as the NATO supreme allied commander in Europe until Pentagon investigators are able to sift through the emails that involve Allen and Kelley.
Dempsey said he still expects Allen to eventually take over the European Command but acknowledged, "I see this investigation and how long it could take affecting that."
In an interview with American Forces Press Service, Dempsey said "I absolutely have confidence" in Allen's ability to continue in command in Afghanistan despite the distraction of the scandal.
Speaking at a news conference in Bangkok on Thursday, Panetta also said he retains confidence in Allen. He added that he knows of no other senior U.S. military officers being linked to the Petraeus investigation.
The Pentagon chief also told reporters he could not rule out the possibility that the Taliban in Afghanistan would try to use Petraeus' admission of an extramarital affair for propaganda purposes. Petraeus was Allen's predecessor as top U.S. commander in Afghanistan.
Petraeus, speaking to the media for the first time since his resignation, said in an interview with CNN that he had never given classified information to Broadwell and that his resignation had nothing to with his upcoming testimony to Congress about the attack in Libya. He also said he wanted to testify about the Libya matter, the network said.