"BGI Group does not engage in unethical practices and does not provide gene technology for the surveillance of Uighurs. BGI Group does not condone and would never be involved in any human-rights abuses," a company statement said on Tuesday.

The statement came after the U.S. Commerce Department on Monday added 11 Chinese companies to its economic blacklist over China's treatment of its Uighurs in Xinjiang in western China.

The companies included two units of BGI, or the Beijing Genomics Institute.

One subsidiary named, Xinjiang Silk Road BGI, "was established in November 2016 and has not carried out actual business so far," BGI said. The other, "Beijing Liuhe BGI" provides commercial gene synthesis for researchers and scientists, the company statement added, saying it is unclear "how its services or products could be used with respect to the allegations made."

The Commerce Department, which did not immediately respond to a request for comment on Tuesday, said the two BGI units were being added for "conducting genetic analyses used to further the repression of Uighurs and other Muslim minorities."

The companies added to the blacklist Monday include Nanchang O-Film Tech, a supplier for Apple's iPhone, which hosted Apple chief executive Tim Cook in December 2017, according to O-Film's website.

Apple spokesman Josh Rosenstock said Tuesday the company has "found no evidence of any forced labor on Apple production lines and we plan to continue monitoring."

Apple has "worked with O-Film for several years and have regularly conducted detailed audits of their facilities," Rosenstock said, adding "Apple is dedicated to ensuring everyone in our supply chain is treated with dignity and respect."

U.S. Senator Marco Rubio, a Republican, praised the Commerce Department's designations "to ensure that U.S. technology does not aid the Chinese Communist Party's crimes against humanity and egregious human rights abuses against Uighurs and other minorities in Xinjiang, including the forced collection of DNA."

By David Shepardson