South Korean President Lee Myung-bak ' s elder brother Lee Sang-deuk will be summoned next Tuesday for questioning over bribery allegations, prosecutors said Friday.

Lee, formerly a six-term lawmaker, is suspected of taking kickbacks from Prime Savings Bank in return for helping the troubled bank avoid regulatory penalties.

Operations of a dozen of savings banks, including the one in question, were suspended last year due to liquidity shortage and illegal lending.

Prosecutors also found some 700 million won (604,800 U.S. dollars) in a bank account of an aide to the 77-year-old former legislator, which they believe might be a potential sign of bribery. The elder Lee has denied all allegations.