China will stop using its long-criticised "re-education" labour camps this year, state media quoted a senior official saying Monday -- only for reports of the news to disappear within hours.

The fate of the announcement -- at once historic but also short-lived -- offered a rare glimpse behind the tightly controlled official version of events in China.

Under the hard labour system people can be sentenced to up to four years of re-education by a police panel, and do not even appear before it.

Most of those condemned to the camps, where they perform manual labour such as agricultural or factory work, are accused of prostitution, drug addiction, or petty criminal offences, although no criminal conviction is necessary.

But opponents say they are also used to silence government critics and would-be petitioners, who seek to bring their complaints against officials to higher authorities.

The system has faced growing criticism for being open to abuse and public anger has erupted in recent months over sentences deemed too harsh.

News of the radical reform came from the official microblog of the CCTV state news channel, which reported the announcement by Meng Jianzhu, one of 25 members of the country's powerful Politburo who oversees politics and legal affairs.

The decision technically still required approval by the national parliament -- a rubberstamp body -- but had already been studied by the more influential central committee of the ruling Communist Party.

"During the meeting Meng Jianzhu also announced that the central committee has looked into the matter, and that after requesting approval from the National People's Congress, the re-education through labour system would stop being used this year," CCTV wrote.

But soon afterwards, the post disappeared, as did other accounts of the statement, including one published on the microblog of a reporter for the Legal Daily and another by the respected Beijing-based publication Caixin.

The curtain of state-controlled media was quickly drawn over the issue, with subsequent Chinese reports of the meeting recounting milder promises of pursuing change.

"The Chinese government will this year push the reform of its controversial re-education through labour system," the Xinhua state news agency said a few hours later.

"No further information on the reform was available for now."