Petraeus inquiry snares top general

Commander in Afghanistan probed for inappropriate communication

The top US commander in Afghanistan, General John Allen, is under investigation for alleged inappropriate communication with a woman at the center of the sex scandal involving former CIA director David Petraeus, a senior US defense official said on Tuesday.

The shocking revelation threatens to fell another of the US military's biggest names and suggests that the scandal involving Petraeus - a retired four-star general who had Allen's job in Afghanistan before moving to the CIA last year - could expand much further than previously imagined.