A former French Polynesian vice-president, Temauri Foster, has lost the mayoralty of the atoll in Hao to a candidate from the Tahoeraa Huiraatira Party of Gaston Flosse.
The Tahitipresse news agency says Suzanne Butcher defeated Mr Foster by four votes in a weekend municipal council vote.
Mr Foster, who has been a senior member of the To Tatou Aia coalition, says during the recent elections there were a number of irregularities that warranted a court challenge.
But he says he wants to be fair player and won't challenge the outcome.
The President, Gaston Flosse, says Hao has been in crisis since the end of the French nuclear weapons testing as efforts to find a new economic base have failed.