The commander of US and NATO forces in Afghanistan has been cleared of misconduct by Pentagon investigators over emails he sent to a Florida socialite, US officials have said.
On Tuesday, the defence department's inspector general completely exonerated General John Allen, the outgoing chief of US-led forces in Afghanistan, paving the way for his pending nomination to take up command of NATO forces in Europe, the official said.
"Allen has been cleared by the [Inspector General] IG," the official told AFP news agency on condition of anonymity.
The FBI came upon the emails from Allen in its probe of David Petraeus - former CIA director - and defence officials had said the tone of the messages had been potentially "inappropriate" and possibly violated rules applying to military officers.
Allen had exchanged messages with Jill Kelley, a Florida socialite who had thrown parties for senior officers at US Central Command, which has its headquarters in Tampa.
Kelley had alerted the FBI to anonymous emails she received and claimed were threatening. The emails were traced to David Petraeus's biographer, Paula Broadwell, and authorities then uncovered evidence that Broadwell was having an affair with the CIA director.
The scandal prompted Petraeus to resign abruptly in November last year, ending a storied career marked by his tenure as military commander in the wars in Iraq and Afghanistan.
The FBI found numerous emails between Allen and Kelley, after which defence secretary Leon Panetta had ordered an independent inquiry by the Pentagon inspector general.
Panetta "was pleased to learn that allegations of professional misconduct were not substantiated by the investigation", and has "complete confidence" in Allen's leadership, his spokesman George Little said in a statement.
Initially, officials had said there were 25,000 to 30,000 pages of correspondence between Allen and Kelley, raising questions that his emails could reflect a distracted commander.
But officials later said the inquiry was only focused on a few hundred messages.
The scandal broke after Allen was nominated to take over as NATO's supreme allied commander, and his confirmation hearings before the US Senate were put on hold as a result.
Throughout the inspector general's inquiry, Panetta and other top officials expressed full confidence in Allen's handling of the war effort in Afghanistan.
Kelley, in her first interview since the case came to light, said on Tuesday the media frenzy over the scandal had been a nightmare for her family, that she never had a romantic link to Allen and that she decided not to press charges against Petraeus's mistress over her allegedly menacing messages.
In the emails sent by Broadwell, "there was blackmail, extortion, threats", Kelley told The Daily Beast. "I knew I was being stalked."
Allen succeeded Petraeus as the top commander in Afghanistan, taking over in July 2011. The four-star general is due to hand over his post to General Joseph Dunford next month.