Police have retrieved a secure mobile phone used by former defense minister Kim Yong-hyun during a raid of the defense ministry headquarters on Thursday. 

The police's special team probing President Yoon Suk Yeol’s martial law declaration sent investigators to the defense ministry building in the raid joined by the defense ministry’s probe team. 

The seized phone is a secure mobile phone equipped with programs to prevent wiretapping and call recording.

The phone is considered crucial evidence in shedding light on the martial law incident as President Yoon and Kim reportedly issued orders to field commanders through secure phones while enforcing martial law.

The special probe team also raided the Capital Defense Command headquarters and seized materials from servers connected to the phones.

In addition, the police have secured materials related to the martial law command from the Joint Chiefs of Staff(JCS).

The materials submitted by the JCS reportedly include surveillance footage for the underground command room inside the JCS headquarters, which was used as the situation room by the martial law command before and after the short-lived martial law order.