Tesla, Mercedes, and GM are being probed by US Senate on whether they use forced Uyghur labor

• The Senate Finance Committee sent letters to car makers about their links to forced Uyghur labor.
• The letters ask the automakers to check their supply chains for connections to the Xinjiang region.
• The Uyghur Forced Labor Prevention Act bans most imports from the Xinjiang region.

The US Senate Finance Committee is looking into whether major car makers are sourcing parts and metals linked to forced Uyghur labor, a Muslim minority group based in Xinjiang, China.

Ron Wyden, a Senator from Oregon and the chair of the Senate Finance Committee, sent letters to Honda, Ford, General Motors, Mercedes-Benz, Stellantis, Tesla, Toyota, and Volkswagen on Thursday requesting specific information related to their supply chains.

The committee requested that the car makers conduct their own supply chain mapping and analysis to identify links to Xinjiang. The committee also asked if they have ever ended or threatened to end relationships with suppliers — including sub-suppliers — over possible connections to Xinjiang.

"Automotive supply chains are vast and complex, but it is vital that automakers scrutinize their relationships with all suppliers linked to Xinjiang," the letters said.

The letters come just weeks after Sheffield Hallam University released new research with what they said was evidence that the car makers in question may potentially be importing materials produced by forced Uyghur labor.

The researchers said they found that at least thousands of Uyghurs have been forced to work in steel and aluminum metal-processing factories in accordance to Chinese government mandates. These metals are used to make car frames wheels, brakes, and bodies.

Kendyl Salcito, one of the researchers involved in the Sheffield study, alleged to Insider that the factory conditions are "utterly appalling."

The letters also come a year after President Joe Biden signed the Uyghur Forced Labor Prevention Act, which seeks to ban most imports from the Xinjiang region.

"The United States considers the Chinese government's brutal oppression of Uyghurs in Xinjiang an 'ongoing genocide and crimes against humanity,'" the letters said.

The Chinese government called US claims of oppression and genocide false, the Wall Street Journal reported.

A Honda spokesperson told Insider that it expects its suppliers to comply with its global sustainability guidelines and "will work with policymakers on these important issues."

Stellantis, the brand behind Chrysler and Jeep, among others, is "taking these matters extremely seriously" and currently reviewing chairman Wyden's letter and claims made in the research, a spokesperson told Insider. Stellantis referred Insider to its code of conduct that its suppliers are expected to meet.

General Motors told the Journal that its policy prohibits any form of forced or involuntary labor, abusive treatment of employees, or corrupt business practices in its supply chain, while a Volkswagen spokesman told the Journal that the company investigates any alleged violation of its policy, saying "serious violations such as forced labor could result in termination of the contract with the supplier."

The other automakers did not immediately reply to requests for comment from Insider or the Journal.

Volkswagen, Honda, General Motors, and Stellantis previously told Insider that they reject forced labor in their supply chains and take accusations of abuse seriously.

The committee said that increased transparency will help the government investigate how effective trade laws are in addressing labor and other human rights abuses in China, according to the letters.

"I recognize automobiles contain numerous parts sourced across the world and are subject to complex supply chains," the letters said. "However, this recognition cannot cause the United States to compromise its fundamental commitment to upholding human rights and US law."