SEOUL (Kyodo) -- A South Korean court on Tuesday approved a warrant request from a joint investigation team for the detention of President Yoon Suk Yeol, who was impeached in December following his brief yet controversial declaration of martial law.

It marks the first detention warrant issued for an incumbent South Korean president. Yoon has claimed he cannot be investigated for treason, asserting that the declaration of martial law is a constitutional act of governance by the country's leader.

The investigators sought the warrant on Monday, and the Seoul Western District Court granted it after Yoon ignored three summonses to appear at the Corruption Investigation Office for High-ranking Officials.

However, Yoon remains under guard at his official residence as the incumbent head of state, raising questions about whether the Presidential Security Service may intervene to stop the execution of the warrant, sources close to the matter said.

Investigators said the warrant is valid until Monday. Yoon has argued he cannot be investigated over insurrection charges under the current system and the request for the warrant should be dismissed.