SEOUL - South Korea's presidential security service has blocked a joint investigation unit's attempt to seize a computer server related to impeached President Yoon Suk-yeol's martial law imposition, local media reported on Wednesday.

The presidential security service notified the joint investigation unit on Wednesday that it cannot assist in any operation for the seizure of a computer server as such actions will not be allowed, citing the protection of confidential military information, according to the investigation team made up of the country's police, the defense ministry and the Corruption Investigation Office for High-ranking Officials.

The investigation team's setback on Wednesday came after another unsuccessful attempt a day earlier to retrieve the computer server under the custody of the presidential security service.