NEW ORLEANS (AP) — Former New Orleans Mayor Ray Nagin was indicted Friday on charges that he used his office for personal gain, accepting payoffs, free trips and gratuities from contractors while the city was struggling to recover from the devastation of Hurricane Katrina.

The charges against Nagin are the outgrowth of a City Hall corruption investigation that already has resulted in guilty pleas by two former city officials and two businessmen and a prison sentence for a former city vendor.

The federal indictment accuses Nagin of accepting more than $160,000 in bribes and truckloads of free granite for his family business in exchange for promoting the interests of a local businessman who secured millions of dollars in city contract work after the 2005 hurricane. The businessman, Frank Fradella, pleaded guilty in June to bribery conspiracy and securities-fraud charges and has been cooperating with federal authorities.