Alexis Sarei says he risks “grave harm” if he returns to Papua New Guinea to sue mining giant Rio Tinto for what Sarei claims was the destruction of the land, health and livelihoods of his fellow villagers during the 1970s and 1980s.

So in 2000 Sarei and 21 others launched a class action under the Alien Tort Statute (ATS) in the U.S. District Court for the Central District of California against Rio Tinto’s British and Australian subsidiaries.