The police found the body of 69-year-old Lee In-won, hanging from a tree along a rural road, some 55 km east of Seoul, and also recovered a suicide note from his car, which was found abandoned nearby, EFE news reported.
Lee, who had 43 years of experience working with the group, was set to be questioned the same day by prosecutors over graft charges that include breach of trust and other irregularities.
Most of Lotte's top management as well as the Shin family - owner of the group - were also under the scanner over various charges, including embezzlement and creation of slush funds.
Lotte, which also has extensive business in Japan, is the fifth-largest "chaebol", the term for large business groups enjoying great economic power in South Korea
Last year, Lotte hit news headlines over a power struggle between founder Shin Kyuk-ho's two sons to gain control of the company.
