(CNN) -- South Korean president Lee Myung-bak apologized to his country for what he called "shameful incidents" involving his family and inner circle on Tuesday.
Earlier this month, his older brother, Lee Sang-deuk was arrested on bribery charges involving two troubled Korean banks. This week, prosecutors in Korea sought arrest warrants for two former aides to Lee on the suspicion of receiving bribes from the same two banks, according to Yonhap, a South Korean news agency.
Lee addressed the nation with a speech that was carried live.
"I came into the office with firm determination to bring a clean political climate," Lee said. "I tried, by returning my entire fortune to the society and donating my salary. I was proud that I thought I brought in good results. But my heart collapsed and I cannot keep my head up after what happened to people so close to me."
"This is all my fault," Lee said.
His brother, Lee Sang-deuk is a former six-term lawmaker and has widely been considered the major force behind Lee's presidential election in 2007. Lee Sang-deuk has remained in a detention center since his arrest on July 11, over allegations he received about half a million dollars from the banks Solomon and Mirae in exchange for exerting influence over officials investigating the banks, according to a court official.
The operations of those two banks were suspended in May for six months by authorities.
In his address to the nation, Lee said he felt pain and regret over the scandals.
"I will receive any criticism as if it is sweet," he said.
Lee is not running for re-election this year because South Korean presidents are limited to a single five-year term. But the recent scandals could affect his political party in the December elections.
"I express sincere apology to the people," Lee said.
Lee's brother is not the first relative of a South Korean president to face criminal charges.
Former President Roh Moo-hyun committed suicide in 2009 amid an investigation into a bribery scandal that had tarnished his reputation. His older brother was convicted and sentenced to prison.
Former President Kim Dae-jung's three sons were also imprisoned for corruption by the end of his presidential term.