Ma Congbo drowned himself while he was at the scene helping the rescue the official Xinhua news agency said.

Over 700 rescuers are battling to save the workers after the Friday accident in the eastern province of Shandong it said adding that four had managed to escape and seven more had been pulled out of the mine.

They have drilled a hole to try to get to one of the places where the workers are trapped and are attempting to bring food and water to them.

Ma was the chairman of the Yurong company which owned the mine.

Accidents in Chinese coal mines killed 931 people last year according to government data while figures for all mining accidents were unavailable.

China the world's largest producer of coal says the number of fatalities is declining. But some rights groups argue the actual figures are significantly higher due to under-reporting.

Anger about industrial safety standards is growing after scores of deaths this year including this month's landslide in the southern commercial hub of Shenzhen and a chemical blast in the industrial city of Tianjin in August.

The cause of the gypsum mine collapse is under investigation Xinhua said.