Bangladesh, June 24 -- In a stunning escalation of South Koreas most dramatic political crisis in decades, the countrys special prosecutor has formally requested an arrest warrant for former President Yoon Suk-yeol, further intensifying the legal battle over his controversial and ultimately failed attempt to impose martial law in December of last year.

Yoon, who was ousted from office in April following a series of damning revelations, had already been arrested earlier this year but was released after 52 days in custody due to procedural errors. He now faces renewed legal jeopardy as the special prosecutor, appointed just weeks ago, accelerates a wide-ranging investigation into what has been described as an attempted insurrection against...