Prosecutors on Tuesday detained a human resources officer of KB Kookmin Bank as they investigate allegations that the bank gave favors to well-connected job applicants.

It is the first time the prosecution has detained someone since it began looking into the bank’s hiring irregularities early last month.

The Seoul Southern District Court issued a warrant Monday to detain the human resources officer, citing concerns that he may destroy evidence.

The HR officer is charged with obstruction of business for taking part in illicit hiring practices.

The nation’s financial watchdog in January filed a complaint with the prosecution against five banks -- KB Kookmin, KEB Hana, DGB Daegu, Busan and Kwangju -- over 22 suspected cases of hiring irregularities after its own inspections in December and January.

According to the Financial Supervisory Service, KB Kookmin Bank had a list of 20 people to whom it gave preferential treatment in the recruitment process in 2015. All of them passed resume screening, and three of them made the final cut.

The three include a grandniece of its holding group Chairman Yoon Jong-kyoo and a child of a former outside director who was deemed the least qualified in resume screening.

The prosecution raided the headquarters of KB Kookmin Bank in early February and found materials related to the hiring irregularities in Chairman Yoon’s office and the recruitment department.

The prosecution secured and went through recruitment files as well as the mobile phones of Yoon and human resources officers.

Early last month, the prosecution indicted without detention a former chief of Woori Bank and five other bank officials for allegedly giving favors in the hiring of 37 job applicants with ties to bank executives, bank clients and high-ranking government officials between 2015 and 2017. The bank’s former Chief Executive Lee Kwang-goo resigned amid the investigation.

By Kim So-hyun (sophie@heraldcorp.com)