A special counsel team investigating the December 3 martial law decree has wrapped up its first round of questioning with former President Yoon Suk Yeol.

Yoon departed the Seoul High Prosecutors' Office in southern Seoul around 1 a.m. on Sunday after the questioning.

He had arrived at the special counsel's office at 9:55 a.m. on Saturday and left nearly 15 hours later, but the actual interrogation lasted about five hours due to a tense standoff between Yoon and the investigation team.

The team, led by special counsel Cho Eun-seok, deemed the first session insufficient and has summoned Yoon for further questioning at 9 a.m. on Monday.

Saturday's session began at 10:14 a.m. and centered on allegations that Yoon ordered the Presidential Security Service to obstruct his arrest in January.

Yoon declined to participate in the afternoon session after a lunch break, objecting to the fact that the lead investigator was a police official against whom he had previously filed a complaint.

The interrogation resumed at 4:45 p.m., shifting to separate charges and being conducted by other members of the special counsel team.

Questioning concluded at 9:50 p.m., after which Yoon spent roughly three hours reviewing the interrogation transcript before returning home.