Oh Dong-woon, nominee for chief of the Corruption Investigation Office for High-Ranking Officials, takes questions from reporters on his way to his temporary office in Gwacheon, Gyeonggi Province, April 28. (Yonhap)

The nominee for the new chief prosecutor of the Corruption Investigation Office for High-Ranking Officials is set to explain multiple accusations against him and his family, including allegations of nepotism, in a confirmation hearing scheduled for Friday.

Oh Dong-woon, a former judge and attorney, was nominated last month to lead the state investigation agency but has since been mired in controversy surrounding the hiring of his wife at a law firm he worked for between January 2018 and October 2019.

Oh's spouse has also been accused of selling a 420 million won ($310,000) strip of land and a building in Seongnam, Gyeonggi Province, to their daughter in August 2020, apparently to reduce taxes.

The daughter paid 48 million won in gift tax in relation to the transfer, which was funded by her parents, but she would have had to pay more if the timing had been later, because the land had been approved for redevelopment in 2019, meaning its value was set to increase.

In a written response to opposition lawmakers sent ahead of his confirmation hearing, Oh apologized for any concern he has caused the public in the wake of his nomination.

“I apologize for not meeting the expectations of the people," Oh said.

“However, please understand that I was not a public official at the time, but a private citizen, a lawyer, who could freely engage in economic activities. In the future, as a civil servant, I will deal with my personal life strictly," he added.

Oh is accused of using his position within a law firm to hire his spouse, identified by the surname Kim, as his driver. After Oh left the firm in 2019, his wife was rehired two years later to do administrative work including the copying and handling of documents.

Kim reportedly earned more than 200 million won ($146,200) over the five years she worked for the firm, roughly equal to the median salary in Korea.

Observers have questioned the hiring process and accused Oh of nepotism. Oh has claimed that his wife was hired in a "legitimate" manner.

Regarding the tax reduction allegations against him, Kim said that he did not break any laws in the process, but admitted that he could understand why the public might not agree with his actions.

The main opposition Democratic Party of Korea issued a statement on the matter Wednesday, denouncing Oh as an "unqualified nominee."

“Oh is an unqualified nominee for the chief of the CIO, and has been accused of dodging taxes and malpractice related to hiring his family at the law firm. Also, if any criminal charges are revealed against Oh, he will be reported," the main opposition said.

Though a confirmation hearing will take place, approval from the Assembly is not mandatory for Oh's appointment.

President Yoon Suk Yeol nominated Oh as the new head of the CIO on April 26. The nomination comes three months after the inaugural CIO chief, Kim Jin-wook, stepped down after his three-year term.