The helmet and lamp of a miner are seen during search operations on the site of the explosion in a coal mine in northeast Colombia on June 18, 2010. Colombian authorities are investigating US mining company Drummond over allegedly dumping coal into the Caribbean, officials said Tuesday.

Colombian authorities are investigating US mining company Drummond over allegedly dumping coal into the Caribbean, officials said Tuesday.

On January 12 and 13 Drummond workers dumped a load of coal into the sea off the northern port of Cienaga to prevent their barge from sinking, alleged Captain Guillermo Diaz, head of the local maritime authority.

"Photographs show there was dumping of coal into the sea. We are determining the exact amount by means of an investigation," Diaz told local media.

Those probing the matter include the country's National Environmental Licensing Authority, the National Mining Agency and the .

Environment Minister Juan Gabriel Uribe said Drummond could face a $1.6 million fine and other sanctions for not reporting the alleged incident in time.

Drummond, based in the US state of Alabama, has been in since 1998. The firm did not return repeated requests for comment.