The defense ministry is looking into allegations that the Defense Psychological Operation Group(DPOG) sent anti-Pyongyang propaganda leaflets across the border before North Korea began floating trash-carrying balloons toward the South. 

According to the military on Friday, the defense ministry questioned the former and incumbent heads of the DPOG and conducted an on-site inspection of the group's base near the inter-Korean border. 

The ministry is said to have focused its probe on whether or not the DPOG reported to higher-rank units about the propaganda leaflet activity and how they came to send the leaflets. 

The probe comes after a soldier who used to be in the Psychological Operations unit said via a media outlet that the DPOG sent anti-Pyongyang propaganda leaflets to the North without reporting to higher-rank units between October 2023 and December of last year in an attempt to essentially provoke an attack from the North. 

The soldier's claim means that the South's military had sent propaganda leaflets to the North before the reclusive state engaged in the activity of floating trash-laden balloons to the South between May and November of last year.