WASHINGTON (Reuters) - With charges expected as early as Wednesday, federal officials investigating the exposure of CIA operative Valerie Plame conducted last-minute interviews with her neighbors and associates of Karl Rove and other top White House aides, lawyers said on Tuesday. Marc Lefkowitz, who lives across the street from Plame, told Reuters two FBI agents asked him on Monday if he knew about Plame's CIA work before her identity was leaked to the press in 2003. Lefkowitz said he told them: "I didn't know."