British customers who visited Radisson hotels in the US between last November and this May have been warned that their credit or debit card numbers may have been at risk.
Radisson Hotels and Resorts informed guests that computer systems in the US and Canada were accessed illegally, and that law enforcement agencies were investigating.
Fredrik Korallus, chief operating officer for Radisson, said in a statement: "The data accessed may have included guest information such as the name printed on a guest's credit card or debit card, a credit or debit card number, and/ or a card expiration date."
He hastened to add that the number of potentially affected hotels involved in this incident was "limited".
Korallus recommended that past guests reviewed account statements and credit reports closely.
He advised that if they did see any unauthorised activity, they should report it to the bank that issued the card as well as the police.
He said: "Radisson values guest privacy and deeply regrets this incident occurred, Working with law enforcement and forensic investigators, Radisson is conducting a thorough review of the affected computer systems."
Korallus said that it had also implemented additional security measures so the attack would not happen again, and was working with major credit card suppliers to make sure the incident was addressed properly.
This week three were accused of carrying out the 'largest identity hack ever', while a security executive detailed how British retailers could learn lessons from the incident.
