A self-proclaimed environmental protection activist has been detained by police amid an ongoing crackdown on online rumors.
Dong Liangjie, 47, has been placed under criminal detention on suspicion of "provocative and disturbing behavior", the Beijing Public Security Bureau said on Saturday.
Earlier reports said Dong was detained on Sept 11 in Suzhou, Jiangsu province, by Beijing police officers. Family members later confirmed the reports.
Dong is well known for his sensational claims on the Sina Weibo micro-blogging service that tap water in China "contains high level of contraceptive substances" with "unpredictable consequences".
He also said an abnormal concentration of lead had been detected in pork sold in Nanjing, Jiangsu province, and excessive levels of copper were found in pig livers in Huizhou, Guangdong province.
The remarks, forwarded by many Chinese Internet users, attracted widespread attention.
Police say Dong has confessed to fabricating all the claims and didn't have evidence to back them up, Xinhua News Agency reported.
Police also claim that Dong admitted to distorting the research findings of foreign experts to support his words.
"I am willing to apologize and would like to suggest that micro-bloggers should not follow my example," Dong said on a China Central Television program aired on Sunday.
"They must strictly abide by professional ethics when spreading scientific knowledge and regulate themselves when posting information online," he said from a detention center.
"They should provide authentic, comprehensive and objective information to the public."
Dong was trying to generate publicity among Internet users and promote his water-purifying products, Xinhua quoted Beijing police as saying.
He founded a company that manufactures environmental protection products after returning to China from the United States in 2008, where he had received a master's degree in environmental protection.
Troubled by poor publicity and a lack of investment, he discovered that micro-blogging sites, which began to bloom in China in 2009, were an ideal platform to gather followers and expand his influence.
He also took the advice of Xue Biqun, a Chinese-American investor who has 12 million followers on Sina Weibo, to use sensational headlines when writing blogs or forwarding news.
Xue, who named himself Xue Manzi on Sina Weibo, was detained in August on suspicion of patronizing prostitutes.
China has taken measures to clean up rumors on the Internet since August, when several people were detained on allegations of fabricating and disseminating rumors or false information online.
The Supreme People's Court and Supreme People's Procuratorate also issued a judicial interpretation that stipulates that individuals face defamation charges if the online rumors they create are viewed by at least 5,000 Internet users or forwarded 500 or more times.