The head of the US Senate Finance Committee has expanded an investigation into BMW after the car maker was found to have imported vehicles into America that contained banned Chinese parts.

In a letter to BMW North America, Senator Ron Wyden, asked the firm for more details about its supply chain, including whether it had now stopped importing banned components.

BMW Group did not immediately respond to a request for comment.

Last month, BMW said it had “taken steps to halt the importation of affected products”.

It came after a two-year long investigation by Senator Wyden’s staff revealed at least 8,000 BMW Mini Cooper cars with banned parts had been imported into the US.

The report found that the cars contained components made by Chinese firm Sichuan Jingweida Technology Group (JWD).

“Is BMW certain that it is not currently importing vehicles containing components produced by JWD?”, Senator Wyden’s letter said, asking for answers by 21 June.

The US Congress passed the Uyghur Forced Labor Prevention Act (UFLPA) into law in 2021.

The legislation is aimed at preventing the import of goods from China’s north-western Xinjiang region that are believed to have been made by people from the Uyghur minority group in forced labour conditions.

JWD was added to the UFLPA Entity List in December 2023, which means its products are presumed to be made with forced labour.

China has has faced accusations of detaining more than one million Uyghurs in Xinjiang against their will in recent years.

Beijing has rejected all allegations of human rights abuses in Xinjiang.