The indictment charges Nagin -- a Democrat who was mayor when Hurricane Katrina struck the gulf region in 2005 -- with 21 counts, including six counts of bribery, one count of conspiracy, one count of money laundering, nine counts of deprivation of honest services through wire fraud and four counts of filing false tax returns.
The indictment alleges Nagin took bribes and accepted gifts from contractors while he was in office.
Frank Fradella and Rodney Williams -- who have pleaded guilty to bribing Nagin to get city contracts -- are expected to testify against the former mayor if the case comes to trial, The (New Orleans) Times-Picayune reported Friday.
Fradella operated Home Solutions of America, described in Securities and Exchange Commission documents as a hurricane restoration company based in Dallas and New Orleans.
Williams is a former president of Three Fold Consultants LLC, which collected more than $3 million from New Orleans on no-bid contracts during Nagin's tenure as mayor, the newspaper said.
Nagin, who left office in 2010 after serving two terms, currently lives in Dallas.