The special counsel investigating former first lady Kim Keon-hee has announced that she will be indicted August 29.

It marks the first time in South Korea that a former first lady will be indicted while in custody, and the first time both a president and spouse face trial while detained, with former President Yoon Suk Yeol already indicted in the martial law probe.

Kim faces multiple charges, having allegedly received luxury gifts and lobbying requests from the Unification Church via shaman Jeon Seong-bae; interfered in political nominations through polling broker Myung Tae-kyun; and financed the Deutsch Motors stock manipulation scheme.

She has refused to answer most questions during four rounds of interrogation since her detention on August 12.

Another questioning session has been rescheduled for August 28 after she cited health reasons to skip one set for the 27th.

With her detention expiring August 31, investigators say the August 28 session will likely be her last before indictment.