The Ritz-Carlton Hotel Company is the latest high profile victim of a data security breach following the attack from hackers on its marketing partner Epsilon that manages customers' emails on behalf of the chain.
Various firms in the US including Citigroup have already had customers' data leaked following the assault on online marketer Epsilon, being described as the largest security violation in the US.
The famous hoteliers have written to customers confirming that the hack had taken place and warning them to be on the lookout for any suspicious activity.
"We were recently notified by Epsilon...that unauthorised third party gained access to a number of their accounts including The Ritz-Carlton email list," the Ritz-Carlton stated.
The information stolen included names and email addressed but customer accounts and "other personally identifiable information are not at risk", it added.
"In all likelihood, this will not impact you. However, we recommend that you continue to be on the alert for spam emails requesting personal or sensitive information," Ritz-Carlton said in the statement.
"We regret this has taken place and apologise for any inconvenience," it added.