The prosecution has requested a pretrial detention warrant for Defense Counterintelligence Commander Yeo In-hyung as part of their probe into the December 3 martial law incident. 

The special team of prosecutors probing the incident said it made the request on Friday. 

Yeo is accused of sending troops to the National Assembly and the National Election Commission and ordering the arrest of key figures, including the chairs of the ruling and main opposition parties, according to commands from former defense minister Kim Yong-hyun. 

Prosecutors also believe that Yeo instructed the command to draft an emergency martial law declaration and was briefed in advance about documents on martial law preparations.  

Yeo was grilled by the prosecution for some 12 hours on Thursday, during which he is said to have told prosecutors that the president had mentioned martial law multiple times at unofficial occasions since this past summer. 

Yeo, who graduated from the same high school as Yoon and Kim, is suspected of being deeply involved in the martial law incident.