Wau Governor Andrea Mayar has denied reports of restricted access and harassment of humanitarian workers in the state.
In June, a fighting between the army and an armed group left about 50 people dead, according to the UN. Thousands sought refuge in UN camps in the area.
Aid groups have been reporting such incidents of restriction at checkpoints along the way from Juba to the state.
Mr Mayar was responding to latest accusations by some organizations that security personnel prevented them from accessing a conflict-affected population outside the town.
“These are baseless allegations,” the governor told Eye Radio. “Let them show me one police officer who happened to be an obstacle to their operation.”
However, the United Nations Emergency Relief Coordinator, Stephen O’Brien, voiced serious concerns during a visit to South Sudan this month, about violence against civilians, as well as attacks against aid workers.
The UN says 57 aid workers have been killed in South Sudan since December 2013 while many more are still missing.