Slavery and indentured labor is widespread in the fashion industry, as I’ve reported in the past. This week, the South China Morning Post reports that China experts have gone to Capitol Hill to explain to lawmakers that American apparel brands may be benefiting directly from coerced labor carried out by Uyghurs, a Muslim ethnic minority living in the Xinjiang autonomous region in China.

The New York Times says that more than a million Uyghurs have been forcibly held in camps and subject to political indoctrination. A United Nations human rights panel said that Uyghurs were being detained in a “massive internment camp that is shrouded in secrecy.” The Chinese government refers to these camps as “vocational training centers.” New evidence has emerged that some of these Uyghurs being coerced to work in factories that make apparel and clothing—and may supply American retailers.

A new report from the Center for Strategic and International Studies (CSIS) paints a bleak picture of how these minorities are picked up and thrown into these camps. “They are reportedly detained for growing a beard, international travel, WhatsApp usage, or for no known reason at all,” it reads. “These detentions combine with an unprecedented and all-pervasive surveillance system that permeates the lives and movements of the minorities who are not detained.”

The Post reports that U.S.-based scholars and experts spoke before legislators about how Uyghurs who have been forcibly held in detention centers have been put to work in factory jobs. Companies that used these factories staffed by Uyghurs would receive government subsidies for each individual trained and employed, along with shipping subsidies. This cheap labor along with the government subsidies would result in very low manufacturing costs, “undercutting global prices,” the Post says. This could turn Xinjiang into hub for low-cost manufacturing.

The CSIS’s report, which included interviews with former detainees, says many of these factories were producing goods for the apparel industry. And in disturbing news for American consumers, the U.S. received many of these exports.

“This forced labor is connected to Western supply chains and consumers, as Xinjiang produces over 80 percent of China’s cotton,” the authors write. “The United States in turn imports more than 30 percent of its apparel from China.”

Even if a product isn’t imported into the United States directly from Xinjiang, it may contain fabrics or components made from the forced labor that happens in the Xinjiang camps. For instance, the U.S. Customs and Border Protection has recently banned all imports from a clothing manufacturer called Hetian Taida Apparel, which is based in Xianjiang. Hetian had supplied pajamas to Costco and shipped 148 tons of clothing to the country, according to the Post.