South Korean investigators have called in arrested President Yoon Suk Yeol for questioning again, the Yonhap News Agency reported, as authorities face a Friday deadline to obtain a warrant to extend his detention or release the embattled leader.

Yoon, who has been suspended from office since his impeachment on December 14, is under investigation for offences including insurrection, which is punishable by life imprisonment or the death penalty, though South Korea has a longstanding moratorium on executions.