The brother, a former six-term lawmaker, appeared at the Seoul Central District Prosecutors' Office around 10 a.m. Prosecutors were asking him about alleged bribery cases, including suspicions that he took some 2.2 billion won ($2.03 million) in bribes from Lee Pal-seung, a former chief of Woori Finance Holdings, ahead of the 2007 presidential election.

Prosecutors suspect the former president could have been involved in such bribery cases.

It was the second time that the brother has appeared at the prosecutors' office for questioning after his first appearance in January to answer questions about allegations that he took illicit money from the state intelligence agency.

The former president, who was in office from 2008-2013, is facing suspicions that presidential aides received at least 1.75 billion won ($1.63 million) from the state intelligence agency at his instruction. While indicting one of Lee's closest aides last month, prosecutors described Lee as the main culprit.

Lee is also at the center of a ballooning scandal involving his brother's auto parts manufacturer, DAS. Prosecutors suspect that Lee is the real owner of the company and has used it as a channel to create slush funds, among other irregularities. (Yonhap)