A leading dissident who organised a charter signed by hundreds of Chinese thinkers, academics and writers calling for dramatic political and legal reforms was under arrest yesterday.

Liu Xiaobo, a literary critic first jailed for his role in the 1989 Tiananmen Square demonstrations, was taken from his home in Beijing late on Monday by a dozen police officers and was asked to sign a document acknowledging his detention. They searched his flat and took away three computers, mobile phones and documents, friends told The Times.

His arrest came hours before the release on the internet of the “08 Charter”, a rare, outspoken document challenging the ruling Communist Party to grant greater freedom of expression and to hold free elections. Its publication was timed to coincide with the 60th anniversary of the Universal Declaration of Human Rights today.

A total of 303 people — from a prominent Tibetan blogger to lawyers and a disgraced former senior Communist Party official — braved possible arrest and jail to put their names to the document. It proposed 19 measures to improve human rights in China, including promoting an independent legal system, freedom of association and an end to one-party rule. “All kinds of social conflicts have constantly accumulated and feelings of discontent have risen consistently,” it read. “The current system has become backward to the point that change cannot be avoided.” China remained the only big power still to retain an authoritarian system that so infringes human rights, it said. “This situation must change! Political democratic reforms cannot be delayed any longer!”

Another organiser of the document, the activist Zhang Zuhua, was detained on Monday night, his computers confiscated and his savings removed from his bank accounts. He remained defiant after being released yesterday. He said: “It was a very constructive document. We asked them which clauses were miswritten and they didn’t say.”

However, there was no word from the Ministry of Public Security as to the fate of Mr Liu, 53. An academic who first came to prominence in the mid-1980s as a literary critic, Mr Liu is no stranger to China’s prisons. He has been arrested repeatedly since he spent 20 months in detention after the 1989 protests. He was jailed for three years in the 1990s but remains among the most outspoken and irrepressible critics of the system.

The Government marked the anniversary of the human rights declaration with a statement of its own, outlining improvements during 30 years of reform. It acknowledged that many problems and difficulties still existed, such as social inequalities and weaknesses in the political structure: “There are quite a few things less than satisfactory in the human rights conditions in the country.”

Mr Liu’s wife, Xia, remained under police surveillance in her home for 12 hours after her husband was taken away, not allowed even to close the door to the bathroom. She was able to make telephone calls only after the police left.

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