Minor Rebuilding Korea Party leader Cho Kuk, who was questioned by the prosecution on Saturday about allegations surrounding former President Moon Jae-in's ex-son-in-law, denied acquaintance with the involved parties.

Prosecutors suspect that budget carrier Thai Eastar Jet's hiring of Moon's then-son-in-law identified by his surname Seo, was linked to the appointment of Lee Sang-jik, the founder of Eastar Jet who also established the Thai airline, as head of the Korea SMEs and Startups Agency in 2018.

The state agency likely questioned Cho regarding allegations that then-presidential aides, including Cho while serving as the senior presidential secretary for civil affairs, had nominated Lee for the SMEs agency post during a closed-door meeting in late 2017.

After being questioned for over three hours as a witness by the Jeonju District Prosecutors' Office, Cho, a presidential aide and justice minister under the Moon government, said he had cooperated as a law-abiding citizen.

Cho said he had testified to the prosecution that Lee's appointment was carried out in accordance with general personnel appointment procedures and practices.