The Demo Site

Teng Biao, a Beijing-based lawyer, said e-mails sent to his Gmail account were being automatically forwarded to another user without his knowledge. Teng said in a phone interview today that he hasn’t yet informed Google about the intrusion, which he discovered yesterday.

Google said this week it boosted protection and security for users after detecting attempts to access data of human rights advocates who subscribe to its services. The operator of the world’s most popular Internet search engine warned it may end its operations in China as the government strengthens censorship of online content and tightens curbs on Web operators.

The government has not commented directly on the Google announcement. China is “firmly opposed to hacking attacks,” said Wang Chen, director of the State Council Information Office, according to a transcript of his remarks posted on the office’s Web site yesterday.

Jessica Powell, a Tokyo-based spokeswoman at Google, declined to comment. The U.S. Internet company said on Jan. 12 that attackers gained private information of two Gmail users, and dozens of other subscribers were being targeted. Powell said Google doesn’t talk about individual cases.

Teng, 36, who offered to provide legal services to individuals arrested in anti-government riots in Tibet in 2008, said he is visited by government security officials once a month, on average. He is a founder of the Open Constitution Initiative, known as Gongmeng, an advocacy group for Chinese rule of law that was closed by the government last year.

He said he found the malfunction at his Gmail account after following advice posted on Twitter Inc.’s Internet blog site.

Google has “evidence to suggest that a primary goal of the attackers was accessing the Gmail accounts of Chinese human rights activists,” according to a posting by the company’s Chief Legal Officer David Drummond on Jan. 12. He said Google now plans to stop censoring results at its Chinese search engine, a move that may lead to the company shuttering its local Web site and offices, pending talks with the government.

Google and at least 20 other companies faced a series of “highly sophisticated” cyber attacks last month, according to Drummond’s statement.

Google’s possible withdrawal follows four years of clashes over censorship and highlights the challenges global companies face operating in a one-party state that controls the flow of information. The government uses what is dubbed “The Great Firewall of China” to block access to Web sites discussing sensitive topics including Tibetan independence and the 1989 military crackdown on democracy protesters in Tiananmen Square.

Chinese authorities shut more than 100,000 Web sites in December in an “escalation” of its Internet censorship efforts, affecting traffic at both Google and a rival local site operated by Baidu Inc., according to Tian Hou, a New York-based analyst with Pali Capital Inc.