Reporters Without Borders, an international group dedicated to freedom of the press, said on Wednesday that Yahoo Inc. helped Chinese authorities in jailing a pro-democracy activist, the third dissident sent to prison on information gathered from the Internet portal.

In linking Yahoo to the jailing of Jiang Lijun, the advocacy group called on the Sunnyvale, Calif., company to remove its email servers from China. Information gathered from Yahoo Web mail was used to convict Jiang, the organization said.

"It is the only way to avoid taking part in the current crackdown against journalists and democrats," the Paris-based group said.

Yahoo said it was unaware of the Jiang case, even though Reporters Without Borders claimed to have met with Yahoo executives on April 10.

"Let us make clear that we condemn punishment of any activity internationally recognized as free expression, whether that punishment takes place in China or anywhere else in the world," Yahoo spokeswoman Mary Osako said in an email. "While we absolutely believe companies have a responsibility to identify appropriate practices in each market in which they do business, we also think there is a vital role for government-to-government discussion of the larger issues involved."

U.S. Internet companies operating in China, the world's second largest market, have said they have to follow Chinese law, no matter how distasteful to Western countries, in order to do business under the communist government. Google Inc., Microsoft Corp.'s MSN and Yahoo, for example, censor their Chinese-language search results at the request of Beijing.

In sticking with their we-have-no-choice defense, Internet companies have called on the U.S. government to pressure Chinese officials to loosen their restrictions on speech.

Yahoo, however, has been taken to task by advocates for its role in the jailing of three Chinese dissidents. In the latest case uncovered by advocates, Yahoo provided information that helped identify Jiang Lijun, who was sentenced to four years in prison for subversion in November 2003 for his online pro-democracy articles, Reporters Without Borders said.

Based on documents obtained by the group, Yahoo Holdings in Hong Kong confirmed that the email account ZYMZd2002 had been used jointly by Jiang and Li Yibing, who is suspected of being a police informer, the group said.