Prosecutors in South Korea sought an arrest warrant against former first lady Kim Keon Hee, a day after interrogating her over suspicions of her involvement in bribery, stock manipulation and political influence-peddling.

"We requested an arrest warrant for Kim at 1:21 p.m. (0421 GMT)," special prosecutor Oh Jung-hee said at a press briefing.

The development comes as former conservative President Yoon Suk Yeol remains in detention for declaring martial law in December.

If the court grants an arrest warrant, it will be the first time in South Korean history that a former president and first lady were both arrested.

Three ongoing separate special prosecutor investigations against Yoon were launched under the new government of left-leaning President Lee Jae Myung. The investigation targeting his wife is one of the three.

Why is Kim Keon Hee being probed?

The charges against Kim include violations of capital market and financial investment laws, as well as political funds laws, Oh added.

Kim was questioned by the investigators for about seven hours on various allegations, including claims of influencing the conservative party's candidate nominations for a parliamentary by-election in 2022.

She is also suspected of receiving gifts through a fortuneteller acting as an intermediary for a Unification Church official in exchange for business favors. The Unification Church is an influential religious organization in South Korea, which critics liken to a cult. 

The prosecuting team said that the charges also include bribery and stock manipulation.

Kim issued an apology for causing public concern. Without saying much, she hinted that she would deny the accusations against her, calling herself "someone insignificant."

The prosecutors also tried to bring in Yoon to question him about the allegations against his wife; however, the attempts failed due to "the suspect's fierce resistance and concerns about potential injury," Oh said without elaborating.

Edited by: Wesley Dockery