The United States' Congressional-Executive Commission on China released a letter to the International Olympic Committee on Wednesday voicing concern over forced labour in the production of uniforms ahead of the Beijing Games. 

The CECC is concerned that Anta Sports and Hengyuanxiang Group, with which the IOC has contracts to produce uniforms, use cotton from the Xinjiang Uyghur Autonomous Region.

China Beijing Olympic flag

The moon is pictured beside the Olympic flag ahead of the Beijing 2022 Winter Olympic Games in Beijing, China, on 12th January. PICTURE: Reuters/Fabrizio Bensch.

"Cotton produced in the XUAR is synonymous with forced labor and the systematic repression that takes place there," the letter said. 

"Forced labor plays an integral role in the genocide taking place against Uyghurs and other predominantly Muslim ethnic groups in the region."

The IOC did not immediately respond to a request for comment. 

The US Government and many rights groups say Beijing is carrying out genocide in Xinjiang. China denies the allegations of human rights abuses. 

"Because Anta and HYX Group both continue to use cotton produced in the XUAR, there is a worrisome possibility that IOC personnel or others attending the 2022 Olympic Games will be wearing clothing contaminated by forced labor," the CECC added in the letter.

Among the commission's requests of the IOC were to make public a "certificate of origin" that HYX Group provided the IOC "that reportedly confirmed that no forced labor was used" in its production. 

The CECC also asked the IOC to explain publicly "assurances" from Anta Sports that its products were not produced through forced labor.

The Winter Olympics run from 4th to 20th February.