The Chinese version of the Wikipedia online encyclopaedia has been unblocked in the region for the first time in more than a year.

According to press freedom organisation Reporters Without Borders, tests carried out by Wikipedia specialist Andrew Lih showed that China's main access providers had unblocked the encyclopaedia.

Lih said that the reopening had prompted internet users to post a mass of new content, making the Chinese version the fastest growing after the English site.

However, sites relating to 4 June 1989, the date of the Tiananmen Square massacre, remain unavailable.

Reporters Without Borders applauded the move as a victory for Wikipedia's refusal to censor itself, and called on other large internet companies to follow its example in the region.

"While Yahoo, Google and Microsoft harp on about how it is impossible to negotiate with the authorities, and that if they refused to censor their search engines they would be expelled from the country, the Wikipedia example proves the contrary," said a spokesman for Reporters Without Borders.

He added that the need to do business with foreign internet companies meant that the Chinese government had to take a pragmatic view.

"There is therefore obviously room for negotiation for the US companies," the spokesman said. "It is not essential to bow down before Beijing and trample on freedom of expression to do business in this country."

Wikipedia was first blocked in October 2005 and China's main search engine Baidu set up an alternative version that discouraged negative comments about the region.