Kim, 63, has been under investigation over allegations that he attended a sex party hosted by construction contractor Yoon Jung-cheon. He arrived at the Seoul Eastern District Prosecutors Office around 12:50 p.m. and entered the building without answering questions from reporters.
Prosecutors plan to seek an arrest warrant for Kim this week, officials said.
Kim took office in 2013 as vice justice minister but stepped down after just six days as the sex scandal emerged.
In 2013 and 2014, he was probed by the prosecution and police over the suspicions but was cleared of the charges due to lack of evidence. Prosecutors resumed the probe in March following a recommendation from a truth panel under the justice ministry.
Kim is alleged to have received bribes worth more than 100 million won ($85,000) from Yoon in exchange for business favors.
The ex-vice minister also faces allegations that he and Yoon sexually assaulted women in 2008.
The sex scandal became publicly known after a video clip was leaked showing a group of men, including one believed to be Kim, having a sex party with about 30 women in a remote villa owned by Yoon.
Kim has denied the allegations. (Yonhap)