A standoff between rival government forces outside the presidential compound in South Korea is a startling development, even for observers used to the country's famously rough and tumble politics.

The man central to blocking investigators from arresting South Korea's impeached President Yoon Suk Yeol has come under the spotlight himself in the political crisis sparked by Yoon's brief declaration of martial law last month.

South Korea's police have been asked to arrest suspended president Yoon Suk Yeol, the Yonhap news agency reported on Monday. Dozens of investigators working for the Corruption Investigation Office for High-ranking Officials (CIO) attempted to execute a court warrant for Yoon's detention on Friday after he ignored three summonses for questioning over his botched attempt to impose martial law on December 3.