Investigators have secured testimony and records suggesting the counterintelligence command pushed for capital-defense troops to join the drill and are verifying the facts, the paper said.

The team is reportedly weighing whether to formally book former Capital Defense Commander Lee Jin-woo over his possible involvement.

Key questions are the drill's nature and whether the troop request bypassed the normal chain of command.

Observers in and around the military say accountability could widen depending on findings.

The special counsel is withholding details, with further steps expected as the inquiry proceeds.