"Currently, they are still trapped about 480m underground," said You Ningfeng, vice-governor of Guangdong province, on Tuesday.
"The chance of survival for the trapped miners is slim after being stranded for more than 55 hours," he added.
As frantic rescue work continued at the Xingning pit, China's top work-safety official was quoted as saying that this latest in a series of mining disasters was a prime example of pit owners flouting safety laws to make money.
The mine was operating without a licence and in violation of local government orders to shut down for inspections.
"This is a typical case in which mine owners make money, miners lose their lives and the government pays the bill," Li Yizhong, director of the State Administration for Work Safety said.
China's mining industry is the deadliest in the world, with accidents killing 2700 in the first half of the year.
China has pledged $370 million to improve safety at mines in the face of strong demand for coal, which accounts for around two-thirds of the country's energy consumption.