The All-China Environment Federation, a nation-wide NGO on environmental issues, has stepped up its fight against marine pollution with a lawsuit against the State Oceanic Administration for "illegally" allowing a US oil company to restart drilling in February after a severe spill in Bohai Bay in 2011.

"The reason we filed the suit is to supervise the State Oceanic Administration to strictly follow the law in dealing with major marine pollution events," Ma Yong, the federation's director of supervision and litigation, said on Tuesday.

"The information released to the public by the administration didn't contain environmental assessments and no public hearing was held, which is required by law after any severe environmental pollution event." He said marine pollution is a major focus of the federation's work.