People can now read a profile of Zhao Ziyang, the Communist Party general secretary purged after the June 4 crackdown, on Baidu Baike, a web-based encyclopaedia similar to Wikipedia run by Baidu, the mainland's largest search engine.
Zhao's entry had long been blocked by internet censors but internet users discovered late on Monday that was no longer the case.
Searches for Zhao on Baidu have also been freed up and generated more than a million hits.
'This could be a signal that the central government wants to free up public discussion about Zhao,' said Professor Zhang Ming, a political scientist at Renmin University in Beijing.
Baidu spokesman Kaiser Kuo declined to comment.
Zhao's sympathies with student demonstrators during the Tiananmen Square protests of 1989 placed him at odds with paramount leader Deng Xiaoping .
He was purged and placed under house arrest, where he died in 2005 at the age of 85.
The Baidu Baike webpage quotes a central government verdict after the Tiananmen protest, saying Zhao was 'supporting turmoil and splitting the party'. But it also acknowledges Zhao's 'contributions to the party and to the people', and more importantly describes Zhao as a 'proletarian revolutionary', praise usually reserved for the death of a top communist leader.
It was an honour that Zhao did not receive when he died. The government kept news of his death low key and prevented any public commemoration. All mainland newspapers carried the same 54-character Xinhua obituary on the day following Zhao's death. It called him a 'comrade' and revealed how he died, but it said nothing about his life or achievements.
'I think Baidu made that up,' Zhang said. 'It doesn't represent official acknowledgement.'
Zhao's appearance on Baike has become a popular topic of discussion on Weibo, Sina's popular microblog service, even though it still blocks searches for his name. Microbloggers praised Zhao for his economic reform policies and his kindness.
'The more than 1 million search results are like 1 million salutes to Mr Zhao,' Beijing Television host Hu Ziwei wrote on her Weibo account
Zhang said: 'If we ponder deeply about this issue, it appears the central government is moving towards reform and democracy.'