South Korea is offering a 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.

A ferry carrying 459 people, mostly high school students, has sunk off South Korea, leaving at least three people dead and nearly 300 missing.

Almost 300 people are still missing after a ferry carrying 476 people, most of them high school students, sank in cold waters off South Korea’s southern coast.