Special prosecutors investigating Yoon for insurrection and foreign aggression incitement believe the audio files could amount to a “smoking gun” – offering evidence he sought to manufacture a crisis to legitimise extending his presidency, observers said.

“Yoon now faces allegations that, instead of fulfilling his duty to protect the people as commander-in-chief, he jeopardised their safety in an unlawful attempt to extend his rule,” Yang Moo-jin, president of the University of North Korean Studies, told This Week in Asia.

“If the North had responded militarily, it could have sparked armed conflict along the border – and potentially escalated into an all-out war,” Yang said.

According to reports from both the conservative Dong-A Ilbo and the progressive Kyunghyang Shinmun newspaper, special prosecutors investigating Yoon on insurrection charges have secured a recording of military officers quoting Drone Operations Commander Kim Yong-dae as saying that the aerial missions were ordered by “V” – believed to be shorthand for the former president.