''If it was properly covered with non-combustible material, clay and vegetation, then it wouldn't have burnt at all,'' he said.

A career firefighter who did not want to be named also said crews were unable to make progress in the northern walls because most of the water mains and sprinkler heads had been removed. ''The main reason we were unable to make any progress in the northern section was because of the water issues. It meant during the early stages of the fire there was no water access to contain it,'' he said.

He said the fire did not take hold in some parts of the mine's northern wall that had been rehabilitated and management was now furiously reinstalling the mains.

A spokesman for mine operator GDF Suez responded that fire services were in place in ''the bulk of the areas impacted''. He said the fire had initially cut power to the mine, reducing water supply and firefighters' ability to battle the blaze for about 12 hours.

The spokesman said the mine plan included ''stringent operating, safety and rehabilitation requirements'', and he blamed arson for the fire that on Friday led to vulnerable people being advised to leave their homes. ''We are alarmed that our business is now threatened with such a serious situation as a result of a reckless act of arson.''