A watchdog led by the Defense Ministry will investigate whether the ministry's upper echelons systematically concealed records about conditions faced by Ground Self-Defense Force peacekeepers stationed in South Sudan, a source said Friday.

The investigation is expected to center on media reports that the GSDF initially planned to make the daily activity logs public but was deterred by a senior civilian bureaucrat in the SDF Joint Staff, which oversees operations of the SDF's three branches.

The revelation adds weight to opposition party claims that the ministry hid the logs in a bid to allow peacekeepers to continue their mission despite the risk that deteriorating security conditions could leave them caught in the middle of an armed conflict.