The American internet company Yahoo! defended itself today against criticism that it supplied information to the Chinese authorities that led to a 10-year jail term for a local journalist, saying it must comply with the law.

"Just like any other global company, Yahoo! must ensure that its local country sites must operate within the laws, regulations and customs of the country in which they are based," Mary Osako, a Yahoo! spokeswoman, said in a statement from the firm’s Hong Kong arm.

Yahoo! actively collaborated with the investigation into Shi Tao, 37, who was sentenced last April, Reporters sans Frontieres (RSF) said this week. His case was one of the most publicised in a recent rash of actions against journalists and internet users.

A copy of the verdict against Shi, a former journalist for the financial publication Contemporary Business News, says that his personal e-mail address was tracked down to his name and his home based on information provided by Yahoo Holdings (Hong Kong) Ltd.

E-mails containing state secrets were found on Shi’s computer and he was sentenced last April to 10 years in prison for leaking those secrets to overseas media.

Chinese legal experts said that Yahoo’s contracts in China to supply its services almost certainly contain a clause under which it is required to provide to the security authorities any information that would otherwise be covered by confidentiality agreements.

"If the police require information then Yahoo must co-operate," said one lawyer, who declined to be identified.

China has no laws to protect private information, making it easier for the police to approach companies such as Yahoo! to demand they provide evidence linked to a suspected crime.

One unusual aspect of the Shi case is that a detailed copy of the verdict against him has been published on the internet in its original Chinese. That itself may constitute a breach of state secrets.

China never allows publication of such a detailed verdict, particularly when it includes the name of a person - or in this case a company - that has provided evidence leading to a conviction, legal experts said.

Families receive a précis of the verdict and sentence, usually after the removal of all details and evidence presented during the trial. It was unclear how the verdict against Shi entered the public domain.

China’s communist leaders are struggling to maintain control of information in the burgeoning internet era, investing heavily in some of the most sophisticated equipment available worldwide to police its cyberspace.

California-based Yahoo! and two of its biggest rivals, Google and Microsoft’s MSN, have already come in for criticism for censoring online news sites and weblogs, or blogs, featuring content that China’s communist Government wants to suppress.

Foreign companies are often more ready than local companies to meet Chinese demands to ban sensitive words from their sites to ensure access to the enormous market, already the world’s second largest.

An experiment by The Times to use some of the most politically sensitive words in chatrooms on domestic sites such as sina.com or Alibaba.com encountered no blocks today.

Last month Yahoo! paid US$1 billion for a 40 per cent stake in Alibaba.com, China’s biggest online commerce firm.

The Committee to Protect Journalists decried what it called China’s "chokehold" on the internet. "We categorically condemn the outrageous prosecution of Shi Tao," its executive director, Ann Cooper, said.

"We call on the Chinese Government and Yahoo to provide a full explanation of the circumstances that led the company to provide account holder information."

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