A few months after reaching the largest corporate settlement in U.S. history, BP faces a class action lawsuit in Mexico over its deadly 2010 Gulf of Mexico oil spill, which a civic group on Dec. 11 said it had filed against the company.

Acciones Colectivas de Sinaloa, a group specializing in consumer and environmental class action claims, lodged the lawsuit against four BP units at a Mexico City court, said the head of its board, David Cristobal Alvarez.

The claim was based on BP’s acknowledgement of the damage caused when the Deepwater Horizon oil rig exploded on April 20, 2010, off the coast of Louisiana, and on studies supporting evidence of environmental damage in Mexico, Alvarez said.

Because the Deepwater Horizon accident did not immediately contaminate the Mexican part of the Gulf of Mexico, no claims were made at the time, he added.

“But with the maritime currents and the air, the contamination has reached the Gulf of Mexico, it’s started to affect people on the coasts of the states in the Gulf of Mexico,” Alvarez said.

The explosion was the worst offshore oil disaster in U.S. history, killed 11 workers and spewed millions of barrels of oil onto the shorelines of several states for nearly three months.

BP said in July it will pay up to $18.7 billion in penalties to the U.S. government and five states to meet nearly all claims from the spill, adding to the $43.8 billion it had already set aside for criminal and civil penalties and cleanup costs.

Alvarez said the Mexican suit was seeking compensation for the environmental damage caused, if that was recognized.

The court would likely need to decide by February or March whether to accept it as a class action suit, he added.

BP had no immediate comment, a company spokesman said.