One week after the company’s Chinese search engine website was apparently hacked, Baidu.com’s chief technology officer has resigned.

In a terse, two-sentence company statement, Baidu stated that Li Yinan is leaving the company for personal reasons, but the company did not state if the resignation will be effective immediately or if he has a replacement.

“We appreciate all that Yinan has contributed to Baidu and we wish him every success in his future endeavors,” stated Robin Li, Baidu’s chairman and chief executive officer.

At 07:00 on January 12, 2010, Baidu.com experienced a massive failure and users in many cities and provinces in China said they were unable to visit the website. The search engine provider published an official announcement, stating that the reason for users’ failure to access Baidu.com was attributed to illegal domain name tampering by its domain name registrar in the United States. However, other media reported that Baidu.com may have been attacked by Iranian hackers because some users saw a banner for the “Iranian Cyber Army” when they tried to access Baidu’s homepage.

Also last week, in a message titled “A new approach to China” and posted on Google’s official company blog, David Drummond, the chief legal officer and senior vice president for corporate development, said the company “detected a highly sophisticated and targeted attack on our corporate infrastructure originating from China that resulted in the theft of intellectual property from Google.”

Rumors are swirling that Google may close its China operations.