The official says investigators have presented senior-level Justice Department officials such as Attorney General Eric Holder with information on the case to make a decision.
Federal investigators have been looking into whether Petraeus provided classified information to his biographer, with whom he admitted having an affair when he resigned from the CIA in 2012.
The official was not authorised to discuss the investigation by name and spoke on condition of anonymity.
The New York Times reported yesterday that prosecutors had recommended to Holder that Petraeus be charged.