A U.S. Congressional Committee on China issued a letter Tuesday urging NBA players to end their endorsements of sportswear companies that use materials manufactured in Chinese slave labor camps.

In a letter to the NBA, the chairs of the bipartisan Congressional-Executive Commission on China pointed out that more than a dozen pro basketball players have inked deals with companies such as China-based ANTA, Li-Ning, and Peak, to sponsor shoes, jerseys, and other types of sportswear. Many of these products are manufactured using cotton from China’s Xinjiang Province, an area notorious for massive camps where inmates serve as forced laborers to make the products and farm the cotton.

“Players have continued to sign new deals with Anta Sports,” said the letter from Senator Jeff Merkley (D, OR) and Representative Jim McGovern (D, MA), Reuters reports.

“We believe that commercial relationships with companies that source cotton in Xinjiang create reputational risks for NBA players and the NBA itself,” the congressmen added.

The committee members note that the U.S. government has officially charged the Chinese government with committing genocide and crimes against humanity in Xinjiang because of the forced labor camps that literally imprison millions of Chinese subjects. The federal government has also moved to bar imports of cotton from the region.

“The NBA and NBA players should not even implicitly be endorsing such horrific human rights abuses,” the letter exclaims.

The committee members added that the companies the players are working with have publicly embraced cotton from Xinjiang cotton, “likely making them complicit in the use of forced labor.”

“We urge the NBPA to work with its members to raise awareness about the ongoing genocide taking place in Xinjiang and the role of forced labor in the production of products made by brands that NBPA members have endorsed,” the congressional committee added.

“We hope that the result of such efforts would be that the players would leverage their contracts with Anta, Li-Ning, and Peak to push these companies to end their use of Xinjiang cotton. Short of that outcome, we encourage players to end their endorsement deals with these companies,” the congressmen said.

The NBA has stubbornly refused to remark about the forced labor camps making so much of the gear that carries the league’s imprimatur. Indeed, NBA Commissioner Adam Silver recently claimed that the NBA’s billion-dollar deals with China are a “net plus” for world diplomacy.

“The political science major in me believes that engagement is better than isolation,” Silver credulously exclaimed in May. “That a so-called boycott of China, taking into account legitimate criticisms of the Chinese system, won’t further the agenda of those who seek to bring about global change. Working with Chinese solely on NBA basketball has been a net plus for building relationships between two superpowers.”

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