A controversial experimental deep-sea mine is being challenged in court by environmental groups who have accused the Papua New Guinea government of withholding key documents about its approval.

Nautilus Minerals Inc, a Canada-based company...wants to extract gold and copper deposits...using a seabed mining technique...members of nearby communities...claim they were not adequately consulted...hold grave concerns over its impact....

...[chief executive of Nautilus Minerals, Michael Johnston]...said the company had been transparent with all the information on the project...