"The gas well that burst belonged to Petrochina, and was drilled under contract by a company owned by its parent, China National Petroleum Corp (CNPC)," read the statement. CNPC owns 90% of Petrochina.

However, the notice said that the final prognosis remained in the hands of the central government and that it would make a final statement once the government releases its assessment.

"The government has sent out an investigation team to conduct a complete investigation of the causes behind this accident. As this investigation has just commenced and is currently undergoing, the company will continue to closely monitor and assess the situation," said the statement.

Although the final death toll has yet to be completely verified, more than 230 people died when an explosion at a Chongqing gas well on 23 December spewed toxic hydrogen sulphide fumes over the surrounding countryside.