Cathay Pacific is warning passengers they may have been caught up in an international data hack of 9.4 million people.
The airline has set up helplines for worried passengers around the world, including New Zealand.
Data accessed included passenger names, nationality, date of birth, phone numbers, emails, addresses, passport numbers, identity card numbers, frequent flyer programme membership numbers, customer service remarks and historical travel information.
In addition, 403 expired credit card numbers were accessed. Twenty-seven credit card numbers with no CVV were accessed. The combination of data accessed varies for each affected passenger.
The airline says there was no evidence that any personal data has been misused.