In a development expected to put more pressure on foreign high-tech companies operating in China, a free-speech group Wednesday accused Yahoo of providing information to the Chinese government that helped it arrest and imprison a cyber-dissident in 2003.
The report by Paris-based Reporters Without Borders said Chinese court documents showed that Yahoo helped authorities identify Li Zhi through his e-mail address and user name.
The former civil servant from Dazhou in southwestern China was sentenced in December 2003 to an eight-year term for "inciting subversion" after posting essays detailing local corruption.
Yahoo officials were not immediately available for comment. The company has acknowledged handing over such information in the past, saying it must obey the laws of the countries in which it operates.
In September, Reporters Without Borders accused Yahoo of providing information that led to last year's 10-year prison term for Chinese journalist Shi Tao.
The group called on Yahoo to release a list of all cyber-dissidents about whom it had given information to Chinese authorities. "How many more cases are we going to find?" the group said in a statement.
Yahoo, Microsoft, Google and Cisco are under growing pressure over their business practices in China.
The four companies have been asked to appear at a congressional hearing next week to address the ethical responsibilities of Internet firms.
Critics say the companies are cozying up to a police state in their headlong quest for profits. The companies say they are only complying with the law.
Microsoft has shut down a popular blog in China, and Google and Yahoo have filtered their Chinese search results in accordance with Chinese government policy.
Cisco has provided equipment used to filter information.
Free-speech groups predicted that more disclosures detailing cooperation with government censors were likely to surface.
"This will add to the pressure on these companies to be more transparent," said Abi Wright, Asia program coordinator with the New York-based Committee to Protect Journalists, which gave Shi an award last year. "User trust is such an important part of their business, and this goes to the very heart of that trust issue."
Companies are under shareholder pressure to enter the China market, which has 100 million Internet users, second only to the United States.
But their compliance with tough Chinese restrictions has threatened to alienate some of their core U.S. and European users, who see this as a break with basic free-speech principles.
"All companies are coming to realize that doing business in China brings benefits but some pretty heavy baggage and costs," said Michael Geist, a professor of Internet and e-commerce law at Canada's University of Ottawa.
"This is very troubling to a lot of people," he said.
Reporters Without Borders reported that 49 cyber-dissidents and 32 journalists were in prison in China for posting articles and criticism of authorities on the Internet.