The Tonga government's actions against the state broadcaster threaten to undermine democracy, according to the Public Media Alliance.
The world's largest association of public broadcasters has written to the King of Tonga to express their concern over changes to the Tonga Broadcasting Commission.
This month government forced the TBC chair to resign and asked the board to sack the general manager.
The moves followed complaints by Prime Minister 'Akilisi Pohiva that the TBC did not support government enough and was unfairly critical.
The president of the Public Media Alliance, Paul Thompson, says his organisation has been observing the changes.