The Tongan government says the Taimi O Tonga newspaper is a foreign concern with a political agenda, and that it had been ruthlessly campaigning to overthrow the country's constitution.
This is one of a series of the reasons given by the government for banning the import of the Auckland-produced paper.
In a statement, the prime minister's office says the paper, showing strong cultural insensitivity, has incited disaffection among Tongans.
It notes that publisher/owner Kalafi Moala is an American citizen and says no foreign-owned publication with such an agenda has a right of entry into any sovereign state.
The government says the paper's approach to stories on politicians, the church and morality are unbalanced and that those facing criticism, or holding opposing views, are not treated fairly.
It also condemns the paper for not joining the Tonga Media Association which would have made it accountable to a common code of ethics.
And the government says to be able to pass judgement on the quality of the journalism, one needs to be able to read Tongan and to be a regular reader of the paper.
It says translations do not provide the necessary knowledge to be able to pass judgement on the paper's performance.
But a noted Tongan academic, Dr Futa Helu, who is the director of the Atenisi Institute in Nuku'alofa, says the paper is neither culturally insensitive nor unbalanced.
"It's the only free press in Tonga and the most popular newspaper and I think the authorities here have been piqued by the fact that it is the only venue for any criticism, public criticism, of corruption and malfeasance which are rife in Tonga."