Choe ordered BAI officials to swiftly figure out what happened and questioned whether it's right to keep Jang on loan to the National Assembly, a BAI official said. The agency has since ordered her return and put her on standby without an assignment pending the investigation.

In the email disclosed by Rep. Lee Tae-gyu of the minor opposition Bareunmirae Party, Jang said she already reported to the BAI that she's likely to be accepted as a visiting scholar, and the audit agency "deems it a highly meaningful decision" to accept her to the institute.

She said she could "lay the important cornerstone to initiate exchanges between the BAI and the SAIS."

Jang also talked about her husband, Hong Il-pyo, who served as a senior aide to former lawmaker Kim Ki-sik. As a lawmaker, Kim took issue with the operations of the think tank, which has received annual funding from South Korea's government since 2006.

Jang said that, if "Kim's behavior brought hardship to your institute," her husband could become "a mediator and help you deal with issues through conversation." Jang's husband, Hong, later joined the presidential office Cheong Wa Dae after President Moon Jae-in took office.

The USKI accepted Chang's application, and she spent a year as a visiting scholar until earlier this year. (Yonhap)