The investigation into President Yoon Suk Yeol’s controversial December 3 martial law declaration has descended into a jurisdictional tug-of-war among South Korea’s prosecutorial, police and anti-corruption agencies, raising concerns about the investigation's clarity and efficiency.

At the heart of the dispute is the Corruption Investigation Office for High-Ranking Officials, which rejected a request from the prosecutor’s office to hand over all cases related to the martial law declaration. Instead, the CIO invoked its legal authority under the Corruption Investigation Office for High-Ranking Officials Act to demand that the prosecution transfer overlapping cases to the CIO.

“The prosecutor's request was to hand over the case, not to investigate it together,” said an official from the CIO. “Rather, it was a situation where the CIO could request a transfer, so we communicated with the prosecutor's office in that direction.”

Prosecutors, however, maintain that they had proposed a joint investigation with the CIO, a claim the CIO disputes. Both agencies remain at an impasse, with the prosecution and police reportedly reviewing the legal grounds for the CIO’s transfer request.

Meanwhile, prosecutors investigating the Dec. 3 emergency martial law situation launched a criminal investigation against the Defense Counterintelligence Command and others by force on Monday.

The prosecution's special investigation team probing President Yoon’s brief martial law declaration announced that it has been conducting raids against the Defense Counterintelligence Command since Monday morning in a joint investigation with the military prosecutors.

More than 50 military prosecutors and investigators are securing materials related to martial law at the counterintelligence-related offices. The search warrants were issued by the military prosecutors from a military court.

The prosecutor's special team also summoned former Army Special Warfare Commander Kwak Jong-geun as a witness for the allegations of insurrection against former Defense Minister Kim Yong-hyun.

Kwak is under scrutiny for deploying troops to the National Assembly during the martial law incident. He claims that former Minister Kim ordered the removal of legislators from the assembly hall, a directive Kwak asserts he refused, deeming it unlawful.

Prosecutors and police have also imposed a travel ban on former Minister of the Interior and Safety Lee Sang-min.

The National Police Agency's special task force on martial law confirmed the emergency measure, while the prosecutors’ special investigative headquarters simultaneously coordinated the travel ban through the Ministry of Justice.

Lee, a key figure in the case and a former high school junior of President Yoon Suk Yeol, will now face questioning as a suspect. He allegedly played a significant role in the martial law decision alongside former Defense Minister Kim Yong-hyun, who proposed the declaration, and Gen. Yeo In-hyung, commander of the Counterintelligence Command, who carried it out.

South Korea's National Office of Investigation officially listed President Yoon Suk Yeol as a suspect in its investigation into the controversial December 3 martial law declaration. The police are reportedly considering imposing a travel ban on the president as part of the ongoing inquiry.

During a briefing held on Monday, an official said that a travel ban is "under review." "We are comprehensively considering factors such as the possibility of overseas travel and will make a decision accordingly."

The police also emphasize that the investigation into insurrection falls squarely under its jurisdiction. The National Police Agency has already formed a specialized team to look into allegations against President Yoon and high-ranking officials, including former Defense Minister Kim Yong-hyun and Korean National Police Chief Cho Ji-ho.

Observers warn that the jurisdictional battles among the agencies could complicate the investigation into Yoon and his associates, who face allegations ranging from insurrection to abuse of power. The overlapping investigations risk duplicating efforts and slowing the fact-finding process, particularly as each agency vies for dominance.

Legal experts note that the CIO’s invocation of its statutory authority to demand case transfers could escalate tensions between the agencies. Under the CIO Act, investigative agencies are required to comply with transfer requests if the CIO claims jurisdiction, but the law’s implementation has often been contentious.