China's Internet watchdog condemned the Chinese-language version of Google on Thursday for "disseminating pornographic and vulgar information."
The China Internet Illegal Information Reporting Center said it had complained twice to Google about the "pornographic and vulgar links" available through its search engine.
"Google China has not conducted the oversight required according to China's laws and regulations, and a large volume of foreign internet pornographic information has entered our borders through this Web site," the center said.
It urged Google to conduct a "thorough clean-up" of its Web pages and also urged authorities to step in and punish the company.
Google and other major Web sites have previously been given a public dressing down for not being quick enough to wipe out targeted content.
The Internet crackdown has been described by analysts as another step in the Communist Party's battle to stifle dissent in a year of sensitive anniversaries, which included this month's 20th anniversary of the government's crackdown on the pro-democracy Tiananmen Square protests in 1989.
The Chinese government recently ordered all new personal computers to carry Internet filtering software designed to block pornographic content, leading to fears China was using its campaign to protect children from "unhealthy" content as a way of tightening censorship.