US general probed in Petraeus scandal The US military is investigating allegations that its senior general in Afghanistan engaged in "inappropriate" communications with a woman at the centre of the sex scandal that brought down the head of the CIA, officials have said. General John Allen, whose confirmation hearing for a new posting as head of the US European command is to be delayed pending the investigation, denies wrongdoing, according to an unnamed senior Pentagon official quoted by reporters travelling with Leon Panetta, defence secretary. The official said the Pentagon was reviewing between 20,000 and 30,000 pages of emails and other communications between Gen Allen and Jill Kelley. Ms Kelley is an unpaid social liaison at MacDill air force base, Florida, headquarters of the US Central Command, under which Afghan operations fall. She is reported to have received threatening emails from Paula Broadwell, David Petraeus's biographer and, as the married former general revealed in his resignation statement from the CIA on Friday, his mistress. The official told reporters there was a "distinct possibility" Gen Allen's emails were connected to the Petraeus matter. But he cautioned against "jumping to any conclusion" before the US military's inspector general had conducted its investigation into Gen Allen's case. The extramarital affair that prompted Mr Petraeus's resignation was discovered when the Federal Bureau of Investigation began probing allegedly threatening emails sent by Ms Broadwell to Ms Kelley, officials have said. In a statement late on Monday, the US Department of Defense said the FBI had a day earlier referred "a matter involving General John Allen" to it. The four-star Marine general will continue to command the International Security Assistance Force in Afghanistan (Isaf). However, the Pentagon statement urged Congress to speed the confirmation process for General Joseph Dunford, who is President Barack Obama's nominee to succeed Gen Allen as head of Isaf. In Monday's statement, Mr Panetta said Gen Allen's "leadership has been instrumental in achieving the significant progress that Isaf, working alongside our Afghan partners, has made in bringing greater security to the Afghan people and in ensuring that Afghanistan never again becomes a safe haven for terrorists." Mr Panetta added that Gen Allen "is entitled to due process in this matter." Gen Allen succeeded Mr Petraeus as the senior US officer in Afghanistan in July 2011. Mr Petraeus, who took the helm at the CIA after his retirement brought an end to an illustrious military career, has consistently denied speculation touting him as a potential presidential or vice-presidential candidate. He came to prominence during the Iraq war when he was one of the main architects of the troop "surge" strategy to counter mounting civil conflict. The Pentagon official was quoted as declining to say whether Mr Petraeus was mentioned in the emails between Gen Allen and Ms Kelley. He would not say whether they involved sexual matters or whether they were thought to include unauthorised disclosures of classified information, the Associated Press reported. Ms Kelley and Mr Petraeus have reportedly known one another for years but there has been no suggestion that they were anything other than friends. The timing of Mr Petraeus's resignation has prompted some Republicans to ask why news of the investigation into the CIA chief emerged only after Mr Obama had won re-election.