The body of fugitive billionaire Yoo Byung-eun was discovered in rural South Korea in July after a weekslong manhunt.
Authorities allege his corruption likely contributed to the ferry sinking in April that killed more than 300 people.
They say Yoo controlled the ferry operator through a complex web of holding companies in which his children and close associates are large shareholders.
Today, Yoo's eldest son, Yoo Dae-gyun, was sentenced to three years in prison over embezzlement and breach of trust, according to Incheon District Court spokesman Jang Joon Ah.
Ten of the late tycoon's associates were also sentenced to up to four years in prison over embezzlement and other corruption charges today, Jang said.
He said prosecutors and Yoo's convicted family members and aides have one week to appeal.
The sinking, one of South Korea's deadliest disasters in decades, caused nationwide grief and fury, with authorities blaming overloading of cargo, improper storage, untimely rescue efforts and other negligence for the deaths.
