The hotel chain had hired a computer security firm to help with the investigation and would continue to work with the payment card networks, InterContinental's spokesman said.
The investigation was first reported by KrebsonSecurity on Wednesday. (bit.ly/2iF3slF)
A pattern of fraud on customer credit and debit cards was seen, that suggested a breach at some InterContinental properties, particularly at Holiday Inn and Holiday Inn Express hotels, the blog reported citing sources.
The news comes nearly four months after InterContinental's Kimpton Hotels & Restaurants said that an investigation had found a malware attack on servers that processed payment cards used at some of its hotels.
The breach follows similar attacks at Hyatt Hotels Corp (H.N) and Starwood Hotels & Resorts Worldwide Inc HOT.N this year.
Reporting by Arunima Banerjee in Bengaluru; Editing by Martina D'Couto