South Korean President Yoon Suk Yeol is under investigation on potential charges of treason and abuse of power following last week's aborted martial law declaration, a senior prosecutor confirmed on Sunday. "Numerous complaints have been submitted, and an investigation is underway in accordance with the process," said Park Se-hyun, who leads a special probe into the incident, according to the Seoul-based Yonhap News Agency. The investigation was announced a day after Yoon narrowly survived an impeachment motion led by the opposition. Despite this, his political future remains in question amid mounting criticism. The main opposition Democratic Party (DP) escalated tensions on Sunday, demanding Yoon's immediate arrest and investigation over the failed attempt to impose martial law. "Suspending Yoon's presidential duties is the only process that accords with the Constitution, and any other measures are unconstitutional and nothing but another act of insurrection," said DP lawmaker Kim Min-seok. The DP also rejected the ruling party's proposal to temporarily transfer leadership of state affairs to the prime minister. "We will not allow for even a minute such an unconstitutional way of governing," Kim added, dismissing the consensus reached between Yoon, the prime minister, and People Power Party (PPP) leader Han. — Agencies