The internet and mobile phones have undermined attempts by China’s secretive rulers to control the news, a senior Communist party official admitted today.

He accused local governments of being “too naive” by continuing to suppress damaging information about corruption or about disasters, and urged party members to be more open with members of the public.

Wang Guoqing, a vice minister with the cabinet’s information office said: “It has been repeatedly proved that information blocking is like walking into a dead end.”

He said governments used to believe that they could muffle 90 per cent of all bad news. But this was no longer the case. In the internet age, he said, the party had to become adept at managing and controlling information, rather than covering it up.

Mr Wang cited a recent slavery scandal, when local officials attempted to conceal the used of forced labour at brick kilns in north-central Shanxi and Henan provinces.

Unable to obtain information from local officials, parents whose children had gone missing used the internet to post messages and to seek information. Their improvised campaign revealed that hundreds, and perhaps thousands, of people had been forced for years to work as slaves, and had been beaten, starved and guarded by dogs.

Mr Wang said that keeping the information out of the media spotlight until the scandal was exposed by crusading journalists left the Shanxi government in a vulnerable position.

Yet even after they were exposed for allowing the slavery scandal to continue for many months, authorities appear to be reverting to the time-honoured way of dealing with crises by imposing censorship. State-run Chinese Central Television has been ordered to play down the negative aspects of the scandal and to stress the government’s successes in catching offenders and bringing them to justice. Parents of missing children have come under pressure not to speak to the media.

Zhan Jiang, a media expert at the China Youth University for Political Sciences, said: “It is definitely more difficult for the Government to control information flows these days. The North Korean government can do it but in China it is not so easy.”

But the Communist Party remains wary of a free flow of information. For example, no date has yet been announced for the most important political event of the year – the party’s congress that is held once every five years and when a new central Committee and Politburo will be chosen. Based on past such events, most Chinese are guessing it will be in September or October.

Mr Zhan said China still had a long way to go towards full transparency, but international influence was a factor in greater openness.

He said: “There are people who don’t want the public to know anything negative. Progress takes time. But there are struggles between the forces of openness and of conservatism.”

Reporters Without Borders, the media watchdog, describes the Chinese Government as an “enemy of the internet”. In its annual report in February, it said China used armies of cyberpolice and spearheaded an increasingly sophisticated movement to restrict the internet.

In January, President Hu Jintao said China’s rulers intended to keep as tight a rein on the internet as they did on traditional forms of the media such as newspapers and television.