The company has said it is mainly interested in mining in areas of rock between existing flooded mine workings, but some of those flooded areas need to be pumped for safety.

BBC: South Crofty tin valued at '?1.5bn'

Contaminated water levels at a flooded disused mine in mid Cornwall have improved, the Environment Agency has said.

BBC: An archive picture of Wheal Jane

Charles Breslin, Philip Hill, Garry Jenkins and David Powell died when the Swansea Valley mine flooded.

BBC: Gleision mine deaths: Prayers for miners and families

Ingeominas reported that the mine flooded but did not speculate on the cause.

CNN: Nine feared dead in flooded Colombian coal mine

The four men died after the Gleision drift mine flooded on 15 September 2011 after a retaining wall holding back a body of water failed.

BBC: Gleision mine deaths: Prayers for miners and families

The water dragged all of us, and the mine was flooded.

CNN: Nine feared dead in flooded Colombian coal mine