Military police stopped a funeral procession and checked a dead body along Wau-Bussere road.
A family member, Thomas Joseph, says the soldier claimed to do a routine check, Radio Voice of Hope reports.
Another family member, Linda Ferdinand Hussein, calls on the authorities to discipline the soldier because he did not show respect to the deceased man.
She complains that many crimes were reported to the authorities, but nothing was done.
Wau municipal authorities declined to comment on the incident.