Reports from French Polynesia say police have detained a spokesman for traditional royal families, Joinville Pomare, for questioning.
The Tahitipresse news agency says he was taken into custody as he was to witness the court appearance of an associate and former minister, Emile Vernaudon.
The report say his detention followed a land dispute in the east of Tahiti during which Mr Pomare had reportedly brandished a firearm.
Riot police were on standby at the court house when Mr Pomare was detained.
He has been a critic of the French colonisation and land policies.