The government Egypt's motive was to stop Ethiopia from continuing with the Grand Renaissance Dam project, set to be Africa's largest.
Construction of the mega dam has sparked tensions.
Dam talks have resumed between the three states, with Kenya providing technical and legal support in efforts to reach a final agreement.
Ethiopia's Water, Irrigation and Energy Minister Seleshi Bekele has pointed an accusing finger at Egypt over recent unrest that followed the death of popular musician Hachalu Hundessa.
The government says the neighbouring country's motive was to stop Ethiopia from continuing with the Grand Renaissance Dam project, set to be Africa's largest.
