Michael Fawer, a lawyer for Mose Jefferson's ex-girlfriend, said Thursday family members told him of the death, The (New Orleans) Times-Picayune reported. Jefferson, 68, had been transferred recently to the hospital in Butner, S.C.
Jefferson was convicted in 2009 on federal racketeering charges.
While he never ran for office himself, Jefferson helped turn his family into one of New Orleans' dominant political dynasties. William Jefferson, who also ran for mayor twice, unsuccessfully, was the first black congressman from Louisiana since Reconstruction when he was elected in 1990. Their sister, Betty, served on the Orleans Parish school board and as a tax assessor.
The former congressman is now appealing a federal conviction, while Betty Jefferson pleaded guilty last year.
Mose Jefferson grew up poor on a small farm in Lake Providence, La. He moved to Chicago as a teenager and learned politics in a city with one of the most formidable U.S. political machines.
He returned to Louisiana in 1981 to help his brother in a run for mayor.