The lack of access in Xinjiang has also made it pretty much impossible for global clothing brands like Patagonia to figure out if their Chinese suppliers use forced labor.

At best, their auditing firms have been offered factory visits by video. At worst, local monitoring staff members are harassed and their offices raided and shut down by the Chinese police…

Speaking out about Xinjiang can unleash fury from nationalistic Chinese consumers, like calls for boycotts and accusations of companies being complicit with Western governments in trying to keep China down. That anger has translated into lost sales totaling hundreds of millions of dollars for companies like H&M and Nike.

Brands are typically keen to showcase actions they have taken against forced labor, but when it comes to Xinjiang many simply avoid the subject altogether. Some fear that speaking out might imperil their other China operations and provoke officials to delay shipments of their goods. Mr. Nova at the Worker Rights Consortium said some brands had given him informal commitments to leave China but on the condition that the information remain private.