Jiang Wei, the head of a government committee on judicial reform, said the government has found widespread agreement among legal scholars and lawmakers on the need to reform the labour camp detention system, and an overhaul is being devised based on that consensus.

Mr Jiang's comments were the firmest indication that after years of debate the government is preparing to revise but not abolish the system – known as "re-education through labour" – that critics say tramples civil rights and is prone to abuse.

Some 190,000 Chinese were being held in 320 re-education centres in 2009, according to a UN Human Rights Council report – in addition to an estimated 1.6 million Chinese held in the formal prison system.

Introduced in the 1950s, labour re-education was originally meant for opponents of the Communist regime. Today, the system allows police to jail people for three years without trial, and a fourth year can be added for bad behaviour. While often used for drug abusers, prostitutes and others accused of minor offences, labour camps have also been used to silence government critics and punish practitioners of the banned Falun Gong spiritual movement.

Mr Jiang, speaking at a news conference, said that the system "plays an important role in maintaining social order," suggesting that the government is unwilling to consider getting rid of it. But, he said, Chinese society had "reached a consensus on the need to reform the re-education through labour system."