SEOUL--South Korean President Yoon Suk-yeol's term in office has been dogged by personal scandals, an unyielding opposition and rifts within his own party, and a rapid fall from grace over his short-lived declaration of martial law last month.

South Korean investigators asked prosecutors to indict the country’s detained President Yoon Suk Yeol over his short-lived imposition of martial law last month, as it accused him of rebellion, abuse of power and obstruction of parliament.