South Korea's suspended president Yoon Suk Yeol remains defiant in his newly-fortified residence, as investigators seek to extend the arrest warrant over his short-lived martial law order.

South Korea's presidential guard and military did not allow investigators to arrest ousted President Yoon Suk Yeol during a tense six-hour standoff at the residence in the heart of Seoul, reports Reuters.

South Korea's political leadership was in uncharted territory on Saturday after President Yoon Suk Yeol resisted arrest over his failed martial law decree, days before the warrant for him expires