The Korean arm of U.K. retail giant Tesco is accused of selling more than 24 million customer details including birth dates, the number of children households and other personal information.
Six current and former Home plus staff including chief Do Sung-hwan and two insurance company officials have been charged.
Several insurance firms purchased this information for 23.17 billion won ($21.14 million), the investigation team said.
Home plus gathered personal information while conducting a free lottery with prizes.
Finite and barely visible print on the lottery coupons stated that the personal information they provided would be sold to insurance companies but most customers were not aware.
Some of the prize winners were also not contacted, the investigation team said.