South Korea’s prosecution will transfer the martial law case surrounding President Yoon Suk Yeol and former Interior Minister Lee Sang-min to the Corruption Investigation Office for High-ranking Officials, amid controversy over “overlapping investigations.”

On Wednesday, the CIO announced that it had concluded with the Supreme Prosecutors’ Office that it will now take over the case involving Yoon and Lee. The move comes 10 days after the CIO requested the prosecution transfer relevant cases under its jurisdiction.

After martial law was declared on Dec. 3, the prosecution, police and the CIO received multiple complaints, which led to the launch of simultaneous investigations.

To prevent overlapping investigations, the CIO filed a request on Dec. 8 to both investigative authorities to transfer relevant cases to its office.

According to the CIO Act, considering the progress and fairness of ongoing investigations and to prevent overlapping investigations, the CIO chief may request that cases be transferred to its office. Prosecutors and police are obligated to comply with such requests.

Following the CIO’s request, a joint investigation unit with the Korean National Police Agency’s National Office of Investigation, the CIO and the Criminal Investigation Command of the Defense Ministry was formed on Dec. 11.

However, the prosecution had continued its investigation, raising concerns over confusion when both prosecutors and the joint investigation unit hit Yoon with dual summons for questioning over the martial law turmoil on Monday.

Following Wednesday’s discussions, the CIO will conduct further investigations into Yoon and Lee. The CIO added that it would also withdraw requests to the prosecution to transfer other suspects’ cases, such as former Defense Minister Kim Yong-hyun and former military counterintelligence chief Yeo In-hyung.

The CIO and the Supreme Prosecutors’ Office said it will “continue to discuss matters together” going forward.

After Wednesday’s agreement, according to the CIO Act, while the CIO has the authority to conduct investigations on Yoon and Lee, it does not have the authority to indict the two suspects. For indictment, the CIO must redirect the case to the prosecution after concluding its investigation.

On Wednesday, the CIO added that Yoon failed to appear for questioning over his martial law declaration following multiple attempts to deliver the summons to Yoon on Monday.

The joint investigation team attempted to deliver a summons to Yoon on Monday at the presidential office and Yoon’s residence, but were declined after the Presidential Secretariat and the Presidential Secret Service declined to accept, saying it was "beyond their scope” of duties after a motion to impeach Yoon was passed at the National Assembly on Saturday. Summons were also sent via express mail to the Presidential Secretariat, but were returned to the CIO.

On Tuesday, CIO Chief Oh Dong-woon told the National Assembly’s Legislation and Judiciary Committee that the CIO would take swift, lawful measures in response to their summons being declined.

Oh also added during Tuesday's plenary session that the CIO is looking into whether criteria are currently met to seek an arrest warrant against Yoon, based on the conclusion that doing so was "most in line with lawful procedures" rather than attempting an emergency arrest without a warrant.

The CIO is currently considering whether to issue a second summons for Yoon.