Japan based Prince Hotels Inc. confirmed a data beach has impacted nearly 125,000 customers.
All affected customers had had made bookings through its official foreign language website from May to August 2017.
The English, Chinese and Korean language website is run by Fastbooking Co, which said the hack took place between June 15 and 17.
Prince Hotels said its Japanese website was not affected.
It said 66,960 customers had credit card information stolen while the remainder of cases involved the theft of personal data including names, addresses, phone numbers and booking information.
Fastbooking announced the breach last week and said a third party cybersecurity firm is still investigating the hack.
"I sincerely apologise for all the trouble. We will work hard on the investigation to find the cause and to prevent any recurrence," said Prince Hotels president Masahiko Koyama.
Fastbooking and Prince Hotels both said there has been no concrete evidence of any credit card fraud committed on customer cards yet.
Prince Hotels, which operates 43 hotels across the country, said 86% of all affected customers were foreign nationals.
