President Lee Myung-bak should take moral responsibility for a snowballing influence-peddling scandal in which a troubled savings bank allegedly bribed influential government officials and politicians to avoid punishment for its irregularities, his prime minister said Thursday.

"President Lee, who appointed top officials in charge of supervising the bank, is morally responsible for the scandal, not legally though," Kim Hwang-sik said during a parliamentary interpellation session.

"I also feel responsibility as the prime minister," he added.

The Busan Savings Bank scandal has jolted the nation for months since the bank was accused of tipping off its employees' relatives and VIP customers about its impending suspension in February so as to help them withdraw their deposits in advance.

The bank was later found to have engaged in extending illegal loans to large shareholders and other financial irregularities involving 7 trillion won ($6.47 billion) in total, leading its chairman, Park Yeon-ho, and several major shareholders to be prosecuted.

Prosecutors have been summoning former and incumbent ranking officials of the country's two financial regulators, the Financial Supervisory Service and the Financial Services Commission, for questioning over their bribery allegations as they recently moved the focus of the probe to the financial authorities.

Kim Jong-chang, a former governor of the FSS, faces summons for his alleged role in drawing the regulator's lax inspection into the bank's illegal loans and other irregularities, according to prosecutors.

Eun Jin-soo, a former state auditor and aide to President Lee, has been arrested on charges of receiving bribes from the Busan-based bank in return for lobbying influential government officials and politicians over the bank's fate. (Yonhap News)