A group of bipartisan lawmakers are demanding an investigation into U.S. drug companies with reportedly troubling ties to China, according to a letter obtained by the Daily Caller News Foundation.

The lawmakers raised alarm to the Food and Drug Administration (FDA) in a Monday letter that they had identified some U.S. pharmaceutical companies as having worked with the Chinese military, raising concerns that U.S. intellectual property is being siphoned off by Beijing. The lawmakers also pointed out that several U.S. pharmaceutical companies also conducted clinical trials in the Xinjiang province of China, a region known for “genocide” against religious minorities, according to a letter sent by the lawmakers to the agency.

Republican Reps. John Moolenaar and Neal Dunn and Democratic Reps. Anna Eshoo and Raja Krishnamoorthi, three of whom are members of the House Select Committee on the Chinese Communist Party, are listed as the signatories of the letter.

The letter claims that U.S. pharmaceutical companies have conducted “hundreds” of clinical trials in China over the last decade, pointing to one example where a company listed the People’s Liberation Army (PLA) as a research partner in trial studies. Other pharmaceutical companies were identified as previously partnered with PLA installations to recruit patients for clinical studies or performed trials at a PLA hospital, according to the letter.

“These collaborative research activities raise serious concerns that critical Intellectual Property (IP) is at risk of being transferred to the PLA or being co-opted under the People’s Republic of China’s (PRC) National Security Law,” the letter sent to the FDA reads. “Conversely, there are also concerns with the trustworthiness of clinical trial data produced overseas from PLA institutions.”

Additionally, multiple U.S. pharmaceutical clinical trials were listed publicly as having been conducted in hospitals in Xinjiang, China, “where credible investigative reports have shown that ethnic minorities in the region are repeatedly forced by the [Chinese Communist Party] to surrender their body autonomy,” according to the letter. The U.S. has accusedthe CCP of committing grave human rights violations against Uyghurs and other ethnic Muslim groups in Xinjiang, including detaining them in internment camps and forcing them into slave labor.

Over 1 million Uyghurs and other ethnic Muslim groups have been detained in internment or detention facilities since 2017, according to a State Department report from June, adding that other estimates put the number closer to three million.

“There are also U.S. biopharmaceutical trials listed on clinicaltrials.gov that were conducted with hospitals located in [Xinjiang],” the lawmakers wrote in the letter to the FDA. “As we know, there is simply no ability for firms to conduct due diligence to ensure that clinical trials done in [Xinjiang] are voluntary. Given this, we believe that U.S. biopharmaceutical entities could be unintentionally profiting from the data derived from clinical trials during which the CCP forced victim patients to participate.”

The lawmakers requested the FDA answer whether it has reviewed clinical trials conducted involving the PLA or at PLA installations, as well as whether the FDA has ever been denied access to clinical sites inside China. They also asked the FDA whether it had made U.S. pharmaceutical organizations aware that it had conducted studies or trials in Xinjiang.

The lawmakers set a deadline of Oct. 1 for a response.

“Data from U.S. biopharmaceutical companies who conducted clinical trials at institutions affiliated with the PLA or other organizations in the XUAR are likely already in FDA’s possession,” the lawmakers wrote. “We therefore request a timely response.”

“The FDA has received the letter and will respond directly to the Members of Congress,” an FDA spokesperson told the DCNF.

Editor’s Note: This article has been updated to include a statement from the FDA.