The family of disgraced former President Chun Doo-hwan pledged Tuesday to pay off a huge amount of unpaid fines, making a public apology for "causing public concern."

In 1997, the nation's top court convicted the former president of mutiny and treason and ordered him to return to state coffers around 220 billion won ($202.15 million) he illegally received in bribes during his iron-fisted rule. Chun has yet to pay some 167.2 billion won he owes. Chun seized power through a coup in 1979 and ruled until 1988.

"I apologize on behalf of our family for causing trouble concerning the payment of fines to the people," Chun's eldest son Jae-kook said at a press conference at the Seoul Central District Prosecutors Office in southern Seoul.

"I'm sorry for being late in resolving the issue due to my inadequacy and realistic problems even though my father told me to cooperate with the authorities as much as I can."

He then announced a list of family assets that will be returned to the state through the prosecution. 

The announcement comes as prosecutors stepped up its search of properties associated with the former military dictator as part of efforts to collect the unpaid money.

In a related development, prosecutors have recently arrested Lee Chang-seok, a brother-in-law of the ex-president, on tax evasion charges. They also questioned the former president's second son, Jae-yong, over his possible involvement in Lee's case.

Lee, the younger brother of former first lady Lee Soon-ja, was indicted last week on charges of evading transfer income taxes worth 6 billion won in the process of selling 28 lots of land that he owned in Osan, just south of Seoul, to a real estate developer in 2006. He falsely reported the sales price to tax authorities to evade the tax, according to prosecutors.

He was the first relative of the former president ever to stand trial since prosecutors restarted efforts to reclaim Chun's hidden assets this year. (Yonhap News)