Xinhua news agency said late on Tuesday that over 30 officials and mine managers have been punished or detained for covering up the mine explosion in Hebei province on July 14, weeks before Olympic Games opened in Beijing on Aug 8.

The deadly blast in the mine in Wei County was set off by explosives illegally stored down the mine shaft.

Relatives of the dead were either bribed or threatened to keep them quiet about the disaster, the report said.

'An investigation has shown that after the explosion, the mine owners and county and township governments colluded to conceal the accident,' the acting governor of Hebei, Mr Hu Chunhua, told officials on Tuesday, according to Xinhua.

'This is a shocking case.'

Hebei is also the home of Sanlu Dairy, maker of the chemical-tainted milk powder that officials have blamed for killing four children and making many thousands sick.

The subsequent detection of the industrial chemical melamine in Chinese dairy products has sparked alarm and product withdrawals in many export markets.

Sanlu and local officials concealed the problem before and during the Beijing Olympics, the central government has said.

After the mine disaster, the corpses were taken away and kept hidden in surrounding areas, where the grieving families were also taken to be paid off, the report said.

'Cash was used to keep them quiet as well as threats and other means, and the miners and their families were not allowed to reveal the facts to the outside,' said the report. -- REUTERS