(Bloomberg) -- Hackers have stolen Nio Inc. user and car-sales data and are now blackmailing the Chinese electric-vehicle maker.

Nio received an email this month in which the sender demanded $2.25 million in Bitcoin in return for not releasing the data, the automaker said Tuesday. An internal investigation revealed that part of Nio’s user and vehicle sales information prior to August 2021 had been compromised.

“The company strongly condemns such unlawful acts and will not bow down to cyber crimes,” Nio said in a statement, adding that it had reported the incident to regulators. It pledged to take responsibility for any potential damages to customers.

Data security issues have become a concern for auto manufacturers and their suppliers. Hackers stole around 40 terabytes of data from German auto-parts maker Continental AG during a cyberattack in August. The loot may include information connected to customers Volkswagen AG, Mercedes-Benz AG and BMW AG, Germany’s Handelsblatt reported last month.

China has demonstrated an increased concern over information-security issues related to intelligent vehicles, as part of a broader oversight on data exports including a crackdown last year on ride-hailing firm Didi Global Inc. Personal information and important data collected and generated within China should be stored in the country, the Ministry of Industry and Information Technology said in guidelines released last year.

©2022 Bloomberg L.P.