American coaches at three NBA training academies in China told league officials their Chinese partners were physically abusing young players and failing to provide schooling, even though commissioner Adam Silver had said that education would be central to the program, according to multiple sources with direct knowledge of the complaints.

The NBA ran into myriad problems by opening one of the academies in Xinjiang, a police state in western China where more than a million Uighur Muslims are now held in barbed-wire camps. American coaches were frequently harassed and surveilled in Xinjiang, the sources said. One American coach was detained three times without cause; he and others were unable to obtain housing because of their status as foreigners.

A former league employee compared the atmosphere when he worked in Xinjiang to “World War II Germany.”