China denies role in Marriott hacking case

Chinese Foreign Ministry spokesman Geng Shuang on Thursday said Beijing opposed "gratuitous accusations" when asked about allegations that clues in a massive breach at hotel group Marriott International Inc implicated China.

Hackers behind it left clues suggesting they were working for a Chinese government intelligence-gathering operation, according to sources familiar with the matter.

Marriott said last week that a hack that began four years ago had exposed the records of up to 500 million customers in its Starwood hotels reservation system. 

Private investigators looking into the breach have found hacking tools, techniques and procedures previously used in attacks attributed to Chinese hackers said three sources who were not authorized to discuss the company's private probe into the attack.

If investigators confirm that China was behind the attack, that could complicate already tense relations between Washington and Beijing, amid an ongoing tariff dispute and US accusations of Chinese espionage and the theft of trade secrets.