WASHINGTON (Reuters) -The chair of the Senate Finance Committee said on Monday he was expanding its probe into German automaker BMW's use of electronic components from a banned Chinese supplier.

Last month, Senator Ron Wyden said after a two-year staff investigation he had learned that BMW had imported at least 8,000 Mini Cooper vehicles into the United States with parts from a Chinese supplier banned under a 2021 law and that BMW continued to import products with the banned parts until at least April.

On Monday Wyden, in a new letter to BMW North America CEO Sebastian Mackensen, asked if the automaker has completed its examination of its supply chain to determine whether other products it imported contained parts from Chinese supplier Sichuan Jingweida Technology Group (JWD).

"Is BMW certain that it is not currently importing vehicles containing components produced by JWD?" the letter said, asking for answers by June 21. Wyden also wants any actions taken by BMW "to address any cars or spare parts containing JWD parts improperly imported by BMW" after December 2023.

BMW Group, which did not immediately respond to a request for comment Monday, said last month it had "taken steps to halt the importation of affected products."

The company will be taking action to replace the specific parts, adding it "has strict standards and policies regarding employment practices, human rights, and working conditions, which all our direct suppliers must follow."

Congress in 2021 passed the Uyghur Forced Labor Prevention Act (UFLPA) law to strengthen enforcement of laws to prevent the import of goods from China's Xinjiang region believed to have been produced with forced labor by members of the country's Uyghur minority group. China denies the allegations.

The report found Bourns Inc, a California-based auto supplier, had sourced components from JWD, which was added to the UFLPA Entity List in December.

Bourns provided JWD parts to Lear Corp, a direct supplier for BMW and other automakers. Bourns notified Lear in January that electronic components known as LAN transformers had been produced by JWD and were prohibited in U.S. imported vehicles.

Lear said last month takes the issues raised seriously and shares "the committee's desire to combat forced labor," and noted it does not have a direct relationship with JWD.