The European Court of Human Rights has thrown out a complaint by a French Polynesian assembly member over a ban to use Tahitian in the legislature.
The court in Strasbourg has ruled that the European human rights convention has no provision to uphold freedom of language.
It says it is not in its powers to decide what language a national parliament should use.
French Polynesia's autonomy statute recognises the Tahitian language as a fundamental element of cultural identity.
The complaint had been lodged by Sabrina Birk in 2006 when the French supreme court ruled that Tahitian wasn't allowed to be used during assembly debates.
The ban is regularly ignored.