Prosecutors have launched a probe into the eldest son of the late owner of the Sewol-ho ferry.
Yoo Dae-kyun was arrested Friday evening in a small apartment he was holed up in Yongin, a city south of Seoul.
The 44-year-old son of Yoo Byung-eun is being held on suspicion of embezzlement related to April's sinking that killed over 300 people.
Park Soo-kyung , a 34-year-old woman, is also being held over suspicions she helped Yoo Dae-kyun avoid the authorities.
Prosecutors plan to apply for court-issued arrest warrants for the two on Sunday.
The focus of the probe is on whether the younger Yoo took part in the management of Cheonghaejin Marine, the company that operated the sunken ferry.
The arrest came a matter of hours after a state agency-led autopsy failed to determine the cause of death for Yoo Byung-eun because his body was too badly decomposed.
Yoo Byung-eun, who disappeared shortly after the ferry disaster, was found dead last month in an orchard in southwestern Korea.