The French Broadcasting Authority says a programme shown this week about the disappearance of a journalist in French Polynesia is of a kind that could influence the outcome of the territory's by-election due in five days.
The authority, known as CSA, wrote to France's TV One, saying the item about an ongoing judicial case was unbalanced and in violation of regulations in place during campaigning.
The programme in question is a weekly current affairs magazine which was this week re-broadcast via satellite in French Polynesia.
The CSA has also ruled that the French Polynesian president, Gaston Flosse, be given the opportunity to express himself on French TV on the subject.
The television report implicated Mr Flosse in the disappearance in Tahiti seven years ago of Jean-Pascal Couraud who was believed to have committed suicide.
The case had been closed but last October a man working as a spy on Mr Flosse's behalf claimed that Couraud had been abducted and drowned by men employed by the presidency.
The former spy was jailed for criminal slander and Mr Flosse swore in the territorial assembly that he had never ordered anybody's death.
Couraud's brother has since lodged a complaint with police for murder in a bid to have the case re-opened.