SHANGHAI, Sept. 20 (Xinhua) -- Police in Shanghai have detained a man suspected of hacking into the database of Huazhu Group Ltd., one of China's largest hotel operators.

The suspect, 30 and identified only by surname as Liu, allegedly hacked into the hotel group's database and attempted to sell the data on websites overseas, but no deals had been made by the time when he was arrested, said the police sources.

Shanghai police launched an investigation into the alleged massive data breach of Huazhu Group Ltd. in August after the hotel group reported the case. According to Huazhu's earlier report, when the online post emerged, it contained nearly 500 million pieces of information related to the hotel group's customers, including registration information, personal data and booking records of the group's wide range of hotel brands.

The police sources said the case is still under investigation, vowing that anyone responsible for the information leak will be punished and they will crack down on any illegal information transactions.

Huazhu is a public company listed in NASDAQ and runs more than 3,000 hotels in more than 370 Chinese cities. It operates more than a dozen brands such as French hotel group Accor's Mercure and Ibis hotels in China as well as Hanting and Crystal Orange.