Aster along with ten other ministers were detained in unknown location ever since. The ministers were criticizing the border war of the then president, Isaia and signed an open letter. He was considered a prisoner of conscience by Amnesty International.
The detention of Aster and the other ministers is linked to their criticism of President Isaia's border war and their subsequent open letter.  Amnesty International has recognized Isaia as a prisoner of conscience due to his actions.