Rep. Chung Doo-un of the ruling aenuri Party, a former close aide of President Lee Myung-bak, nderwent 14 hours of questioning until late Thursday night about llegations of receiving illegal political funds from a candal-ridden savings bank.

"I gave a full explanation on all allegations (of bribery),"Chung told reporters as he left the Supreme Prosecutors' Office in southern Seoul at 11:45 p.m. Thursday. He was intensively questioned on suspicion of receiving approximately 100 million won($83,300) from the now-suspended Solomon Savings Bank in 2007.

The 55-year-old Chung, a three-term lawmaker, refused to elaborate, but prosecution sources said the lawmaker denied the allegations of bribery.

His summons came two days after Lee's older brother, Lee Sang-deuk, was questioned over allegations that he had taken nearly 600 million won ($528,169) from two troubled savings banks, including Solomon, since 2007.

Chung worked as a key campaigner for President Lee during the 2007 presidential race but became estranged from the Lee family later. He served as a member of the Supreme Council for the ruling party from 2010 to 2011.

Lim Suk, the imprisoned chairman of Solomon Savings Bank, allegedly bribed influential politicians and government officials to keep his ailing bank afloat. The bank had its business suspended in May due to a lack of capital and illegal business practices, while Lim was arrested and later indicted.

Chung is also suspected of having introduced Lim to the elder Lee and being present when Lee allegedly took part of the money.

The recent summonses have been a humiliating blow to President Lee during his final months in office.

Meanwhile, prosecutors have reportedly secured statements from the elder Lee and the chairman of Mirae Savings Bank, who reportedly lobbied him, that Kim Deog-ryong, formerly a five-term lawmaker, introduced them to each other.

But prosecutors said they are not planning to summon Kim for now because the mere introduction does not constitute a crime. Kim was one of six key senior mentors known to have helped President Lee win the presidency. (Yonhap News)