A special counsel team has again summoned the head of the Drone Operations Command for questioning in connection with its investigation into the December 3 martial law case.

Special Counsel Cho Eun-suk's team began questioning Kim Yong-dae at 10 a.m. Sunday at its office in southern Seoul, just three days after a previous 12-hour interrogation session.

The probe centers on allegations that former President Yoon Suk Yeol ordered the deployment of drones to Pyongyang in an attempt to provoke a military response from North Korea, potentially laying the groundwork for declaring martial law.

Investigators are also examining claims that the planning and execution of the drone operation bypassed the standard Joint Chiefs of Staff (JCS) chain of command and that Kim Yong-hyun, then head of the Presidential Security Service, was involved in the deployment.

Lee Seung-oh, chief director of operations at the JCS, was also summoned for questioning on Sunday.

The special counsel is investigating whether the drone operation adhered to proper command protocols and whether it was reported to JCS Chairman Kim Myung-soo in a timely manner.