Three other family members — Yoo’s mother and two uncles — have also been arrested on charges of embezzlement from the business group including Chonghaejin Marine.
Yoo’s sister, Yoo Sum-Na, 48, is currently fighting extradition from France on similar charges.
The badly decomposed body of Yoo’s father, Yoo Byung-Eun, who in addition to his substantial business interests also ran a religious group, was found in June. He had been the target of a massive manhunt connected to the ferry sinking.
“I am sorry,” Yoo said to the court before bowing to the judge, the prosecutors and the audience in turn.
Yoo’s defence lawyer has called for leniency in the sentencing, expected on November 5, stressing that Yoo will dispose of all his assets to help compensate for the victims.
Prosecutors are also questioning one of the late Yoo’s key aides — who was repatriated from the US Tuesday — over assets the Yoo family may be hiding.
Kim Hae-Kyung, 52, who was arrested in Virginia in September, is suspected of involvement in the embezzlement of about $23 million from the religious organisation headed by the elder Yoo.
Lee, 69, and three senior crew members are accused of “homicide through wilful negligence” — a charge that can carry the death penalty.