The decision to sack Piveni Piukala was made by Cabinet last Friday, reports Kaniva Tonga News.
A government statement said the grounds for termination included incompetence, acting in bad faith, and failure to follow due process in appointing the chief executive of the Tonga Broadcasting Commission, or TBC.
On Wednesday, the TBC reported the termination followed Mr Piukala's decision to decline a request from the prime minister to suspend three TBC staff members and to investigate them for alleged misconduct.
The staff members are news reporters Salamo Fulivai, Vilisoni Tu'inia and the Station Manager Setita Tu'i'onetoa.
However, Mr Piukala has said sufficient evidence was not given by the prime minister for him to act on the request.
He said under TBC policy for staff to be suspended, the evidence should be given to staff to respond to within 14 days.