Prosecutors indicted Kwon Yoon-Ja, 71, for siphoning off some USD 28 million from a business group that owns Chonghaejin Marine Co., the operator of the ill-fated Sewol ferry.
A district court in Incheon City also sentenced her brother Kwon Oh-Kyun to five years in prison for pocketing the diverted funds.
Kwon Yoon-Ja is the widow of Yoo Byung-Eun, the late patriarch whose family controls Chonghaejin and its affiliates.
Their son, Yoo Dae-Kyun, was sentenced last month to three years in prison for siphoning off some USD 7.2 million from Chonghaejin Marine and its six sister companies between 2002 and late last year.
Yoo's sister, Yoo Sum-Na, is currently fighting extradition from France on similar charges as his younger brother, who is still abroad and wanted by police, is also linked to charges of embezzlement from the family-run conglomerate.
Following the ferry sinking, a manhunt was launched for the reclusive tycoon.
The badly decomposed body of the elder Yoo, who in addition to his substantial business interests also ran a religious group, was found in June. Post-mortem autopsy failed to determine the cause of his death.
