Police will summon the counterintelligence chief and former interior minister as suspects in a sprawling investigation into the short-lived martial law imposition last week, officials said Monday.

The police notified the head of the Defense Counterintelligence Command, Lt. Gen. Yeo In-hyung, and ex-Interior Minister Lee Sang-min of the plan, according to police officials.

The exact date for their appearance has not yet been decided, they added.

Yeo was suspended from his duties last week, and former Interior Minister Lee stepped down from his post Sunday.

Earlier in the day, prosecutors raided the DCC headquarters in Gawcheon, just south of Seoul, as part of their separate investigation into alleged treason in connection to the martial law fiasco.

Military prosecutors also participated in the raid, and the search warrant was issued from the military court. The offices and residences of Yeo and other ranking command officials, and the DCC's branch offices in Seoul and other areas nationwide were reportedly included in the raid.

The moves came after President Yoon Suk Yeol abruptly declared martial law last Tuesday but lifted it hours later after the National Assembly voted to call for its end.

The DCC is known as a key institution in the martial law declaration, reportedly sending troops and personnel to the National Assembly and the National Election Commission.

Opposition lawmakers have also raised suspicions that the DCC had drafted a martial law decree last month under Yeo's instruction and orchestrated the alleged drone infiltration to Pyongyang at the direction of then Defense Minister Kim Yong-hyun.

Yeo denied the allegations, claiming the DCC was not aware of any plans for the martial law declaration in advance.

"I will take full responsibility for all the actions I took as a commander," Yeo said in a statement to the press, vowing to fully cooperate with the ongoing investigation. (Yonhap)