Up to 300 members of the French Polynesian intervention group have blocked access to the main port in Tahiti, laying a chokehold on imports of fuel.
The protesters have barricaded the bridge of Motu Uta, preventing all access to the port area beyond.
The group is calling for the regrading of 200 employment contracts, and for its members to choose their own boss.
The group is threatening to extend its blockade to the east and west entrances of the capital, Papeete.
A spokesman for the presidency, Jacqui Drollet, says he doesn't understand the reasons behind the blockade.
The group, known as the GIP, was set up by former president Gaston Flosse to help out in disaster relief operations.
It's role has since increased to the point where the-then opposition leader, and now president, Oscar Temaru, described it as a 'veritable Praetorian guard' in the service of the powerful.
Since Mr Temaru became president he's been faced with the problem of regrading the employment contracts of the GIP's 800 members.