The ousted Bougainville Chief Secretary, Joseph Nobetau, has launched legal action over his sacking.
President John Momis said Mr Nobetau's relationship with the Bougainville Government had become untenable and that he often seemed to be working for the Papua New Guinea Government against the autonomous region's interests.
But Mr Nobetau said he has never provided anything but loyal service.
He also said the Bougainville government did not have the power to remove him and that responsibility rested with the Bougainville Senior Appointments Committee as laid out in the Bougainville Constitution.
Mr Nobetau told the Post Courier newspaper if the government had concerns these needed to be put to the committee for it to consider.