Hong Kong flag carrier Cathay Pacific said Wednesday it had suffered a major data leak affecting up to 9.4 million passengers.
The airline admitted data including passport numbers, identity card numbers, email addresses and credit card details was accessed.
"We are in the process of contacting affected passengers, using multiple communications channels, and providing them with information on steps they can take to protect themselves," Cathay Pacific Chief Executive Officer Rupert Hogg said in a statement on the airline's website.
"We have no evidence that any personal data has been misused." Cathay said it had launched an investigation and alerted the police after an ongoing IT operation revealed unauthorised access of systems containing the passenger data of up 9.4 million people.
Hogg added: "The following personal data was accessed: passenger name, nationality, date of birth, phone number, email, address, passport number, identity card number, frequent flyer programme membership number, customer service remarks, and historical travel information."