SEOUL, South Korea (AP) — South Korea is offering a $50,000 reward for information about a mysterious missing billionaire who authorities say owns a ferry that sank last month, leaving more than 300 people dead or missing.

The disappearance of Yoo Byung-eun and his son has caused a media frenzy in South Korea. Yoo is a member of a church that critics call a cult and have linked to a 1987 mass suicide; church members deny involvement.