The elder brother of South Korea's president was arrested this week and detained during a widening bribery investigation.
Lee Sang-deuk, 76, was accused of taking $525,000 from the chairmen of two savings banks from 2007 until last year to help them avoid official audits.
One of the banks -- Solomon Savings Bank -- failed two months ago. The other was Mirae Savings Bank.
The BBC said recent bank failures in South Korea have caused nearly 90,000 people lose their savings. Twenty banks have been closed this year.
When Lee Sang-deuk appeared at court after his arrest, depositors threw eggs at him, the BBC said.
Almost 200 lobbyists, politicians, and bankers have been indicted so far in the savings bank scandal.
Zhang Min is a researcher with exthiXbase.