The cousin, also surnamed Cho, was arrested at Incheon International Airport earlier in the day on embezzlement charges, according to officials.

After being transported to the Seoul Central District Prosecutors' Office, the cousin is currently being interrogated, the officials said.

He is allegedly the de facto head of controversial private equity fund Co-Link PE.

Co-Link invested 1.4 billion won (US$1.17 million) in local company Wealth C&T, whose sales soared while Cho was serving as senior presidential secretary for civil affairs.

Co-Link is also alleged to have falsely reported to the financial regulator that it received 7.4 billion won from Cho's family for investment, despite the pledged amount being 1.05 billion won.

The arrest came as prosecutors are widening their probe into the corruption allegations surrounding the justice minister.

Despite the allegations, coupled with suspicions regarding his daughter's education, Cho was sworn in as justice minister on Monday and said that he will not interfere with the ongoing probe. He ordered the prosecution to conduct the investigation in a fair and strict manner. (Yonhap)