SOUTH KOREA鈥檚 former first lady Kim Keon Hee arrives at the special prosecutor鈥檚 office in Seoul, South Korea, Aug. 6. 鈥 REUTERS/KIM HONG-JI

SEOUL 鈥 The wife of former South Korean President Yoon Suk Yeol interfered in state affairs in return for expensive valuables and money, a special prosecutor said on Monday.

The special prosecutor鈥檚 investigations, which wrapped up on Sunday, came amid a year-long probe into Mr. Yoon鈥檚 brief imposition of martial law last year and related scandals linked to the once-powerful couple.

The prosecution team earlier this month sought a 15-year prison sentence for former First Lady Kim Keon Hee, who is under detention and currently on trial for suspected acceptance of bribes for mediation and other charges.

Ms. Kim has denied any wrongdoing. She apologized to the public for causing concerns during a court hearing earlier this month.

Ms. Kim 鈥渢ook advantage of the status of the president鈥檚 spouse to receive money and expensive valuables, and has been widely involved in various personnel appointments and nominations,鈥 special prosecutor Min Joong-ki said at a news conference marking the end of his investigation.

A lower court ruling on Ms. Kim is expected on January 28.

鈥淚nvestigations do not end because one says so, but are eventually completed with evidence in court,鈥 Ms. Kim鈥檚 lawyers said in a statement on Monday, adding they will work 鈥渢o ensure that procedural legitimacy and defense rights are thoroughly guaranteed so that facts are not exaggerated or distorted into political framing.鈥

The prosecution team has also indicted Unification Church leader Han Hak-ja,聽now on trial, after the religious group was suspected of giving Ms. Kim valuables including two Chanel bags and a diamond necklace as part of its efforts to win influence.

Ms. Han has denied that she directed her church to bribe Ms. Kim.

鈥淰arious people who did not have a common denominator with each other visited Kim Keon Hee, not the president, and asked for what they wanted, and gave money and goods,鈥 said assistant special prosecutor Kim Hyeong-geun.

鈥淎s a result, their request was realized.鈥

Ousted President Yoon is on trial for suspected masterminding of an insurrection, a charge that could mean a life sentence or even a death penalty. He has denied the charges.

A lower court ruling on Mr. Yoon is expected early 2026. 鈥 Reuters