The company said payment-related information, such as bank account details and payment card details, and other highly sensitive data, such as personal codes and home addresses, had not been stored in the leaked database.
Svaros Broliai said customer data of other businesses run by the company – tunnel car washes, premises cleaning services and self-service car washes – were secure, based on the currently available information.
"Today we received information that data of some of the customers of Svaros Broliai's car cleaning centers might have been leaked. Unfortunately, this information proved to be correct after checks were made," Lina Zagariene, the company's director, said in a statement.
The data are believed to have been stolen by hackers from Russia, according to the director.
"Hackers from Russia are suspected to have gained unauthorized access to the database of the reservation system of our cleaning centers and to have stolen the information of about 50,000 customers," she said.
Svaros Broliai has blocked the booking system while the investigation is ongoing and has informed its customers, the State Data Protection Inspectorate and law-enforcement authorities about the incident.
The company operates five car cleaning centers in Vilnius.