A special counsel team probing the martial law incident summoned Lee Seung-oh, the chief director of operations at the Joint Chiefs of Staff(JCS), over allegations that former President Yoon Suk Yeol ordered a drone operation into North Korea to create a pretext for declaring martial law.

According to sources in the legal community on Thursday, the team began questioning Lee about the details in the execution of the drone operation and the channel of briefing.

Investigators are also focusing on whether there were orders from Yoon or former Defense Minister Kim Yong-hyun, after reportedly obtaining an audio transcript of an officer suggesting that Yoon had bypassed the defense ministry and the JCS to directly order the Drone Operations Command.

There are also allegations that the Defense Counterintelligence Command knew about the drone operation in advance and attempted to conceal the matter.

The special team, which raided 24 military-related locations on Monday as part of its investigation into the offense of aiding foreign aggression, began grilling Drone Commander Kim Yong-dae on Thursday as a suspect in the case.