Park Chong-jun, center, former chief of the Presidential Security Service, leaves the Joint Investigation Headquarters in western Seoul, Jan. 10, after police questioning regarding allegations that he blocked investigators' attempt to arrest impeached President Yoon Suk Yeol. Yonhap

The former head of the Presidential Security Service (PSS) appeared before police Saturday for questioning over allegations that he blocked investigators' attempt to arrest impeached President Yoon Suk Yeol over a martial law probe.

Park Chong-jun, who stepped down as chief of the PSS the previous day, has been booked on charges of obstructing official duties as presidential security officials have blocked the Corruption Investigation Office for High-ranking Officials (CIO) from executing the warrant to detain Yoon.

Park appeared at the Joint Investigation Headquarters in western Seoul at around 9 a.m. for the second day of questioning following his initial appearance, Friday.

On that day, Park submitted his resignation shortly before appearing for a 13-hour police questioning, following two prior refusals to comply with police requests.

The CIO secured a new arrest warrant for Yoon, Tuesday, after an initial seven-day warrant expired, and is coordinating with police on the second attempt to arrest Yoon.

Separately, Lee Jin-ha, the PSS' head of the security and safety division, who also faces charges of obstructing official duties, appeared before the police at around 1:55 p.m. after two summonses.

He is the second PSS official to appear for police questioning.

Meanwhile, PSS Deputy Chief Kim Seong-hoon, the current acting head of the service, snubbed the police's request to appear for questioning for the third time, Saturday, saying the seriousness of his duties in protecting Yoon makes it impossible for him to step away from his post even for a brief moment.

Kim is expected to lead efforts to stop the execution of the second arrest warrant since Park has resigned.

Police are also likely to seek an arrest warrant against Kim as he has ignored three summonses. (Yonhap)