The Financial Supervisory Service(FSS) has launched a special investigation into suspected unfair hiring practices at KEB Hana Bank after the head of the watchdog offered to resign apparently over his alleged involvement in a related incident. 

The FSS said on Tuesday that a special investigative task force led by its assistant governor Choi Seong-il was dispatched to the bank and its holding group, Hana Financial Group, earlier in the day. It said the probe will run through April second but can be extended if necessary, emphasizing it will be conducted in a fair and objective manner. 

The move comes after FSS Governor Choi Heung-sik informed the presidential office of his intent to resign apparently over allegations he pulled strings to help a friend's son land a job at the bank, although he did not reveal the exact reason for his departure. 

The FSS said the investigation will focus on Choi Heung-sik, who is suspected of passing on the name of his friend's son to recruitment managers at KEB Hana Bank in 2013, when he was president of Hana Financial Group.