Prosecutors are questioning a former aide of ex-President Lee Myung-bak on charges of accepting bribes from the National Intelligence Service(NIS).

The Seoul Central District Prosecutors' Office summoned Kim Paik-joon, former senior presidential secretary for administrative affairs, for a second time on Saturday as he failed to show up for the first summons on Friday.

Kim told reporters waiting in front of the prosecutors' office that he would faithfully undergo questioning. 

Kim is considered a close confidant of former President Lee and is nicknamed "Lee's butler." He is accused of taking illegal bribes from the NIS in the name of "special activity funds" during his years at the top office.

The prosecution believes more than 500 million won of the spy agency's funds were given to three former aides of Lee including Kim.

Prosecutors searched the homes and offices of Kim Paik-joon, Kim Hee-joong and Kim Jin-mo on Friday morning and summoned them all as suspects but Kim Paik-joon did not show up.