French Polynesian unions say they want materials to build the South Pacific's biggest fish farm to be shipped via Papeete.
The Chinese company Tahiti Nui Ocean Foods plans to set up a $US320 million fish farm on Hao atoll, which used to be a military base for the French nuclear weapons tests.
According to a senior union leader Mahinui Temarii, there is an agreement with the territorial government that international shipments need to be processed in Papeete.
He has told the local broadcaster La Premiere that the unions would object to the materials being sent from China directly to Hao.
French Polynesia's shipowners association is also concerned that Papeete may be bypassed.
The Chinese company has been exempted from paying tax for 30 years on the importation of materials and fuel for the project.
The project on Hao, which has been downgraded twice, appears to have been delayed.
Tahiti Nui Ocean Foods is part of the Chinese Tianrui Group, which is active in among others cement, foundry, tourism and mining.