The wife of Cho Kuk who was being questioned by prosecutors for the fifth time on Monday asked for the questioning to end and returned home.
The Seoul Central District Prosecutors' Office had summoned Professor Chung Kyung-shim at 9:30 a.m.
However, following media reports of Cho's resignation on Monday afternoon, Chung asked for a halt to the investigation and returned home a quarter past 3 p.m.
Previously, she had usually returned home late at night during past interrogation sessions.
Cho also left the Justice Ministry and reached his residence at around 4 p.m.
Prosecutors plans to call in Professor Chung again as the fifth interrogation ended inconclusively, and will also review whether to seek an arrest warrant.
The prosecution earlier wrapped up looking into allegations that she had fabricated a school award certificate to help her daughter gain entry into medical school. The probe is now focused on suspicions surrounding the Cho family's investment in a private equity fund.
Chung has denied all the allegations against her.