The head of French Polynesia's Tahoeraa Huiraatira Party, Gaston Flosse, has been fined $US20,000 for defaming the president Edouard Fritch.
The criminal court in Papeete released its verdict after hearing the complaint lodged by Mr Fritch who is the leader of the ruling Tapura Huiraatira party.
Mr Fritch said on two days late last year Gaston Flosse had wrongfully claimed that he had used illegal means to win the territorial election.
Last May, the Tapura won an overwhelming victory, securing two thirds of the assembly's seats.
In September, the Tahoeraa's most senior politician in the assembly Geffry Salmon was fined $US5,000 for making the same defamatory statements about Mr Fritch.
Mr Fritch, who is a former son-in-law of Gaston Flosse, was his deputy for decades, but the two fell out after Mr Fritch assumed the presidency in 2014 when Flosse was ousted from public office for corruption