FBI spokeswoman Laura Eimiller said the probe continues into how Gilberto Sanchez, 47, of New York City obtained the copy he posted to Megaupload.com in the spring.
When the leaked movie made it to the Web, officials from Twentieth Century Fox, the unit of News Corp that was behind the film, expressed their dismay out of a concern that it would undermine the box office appeal of Wolverine.
Sanchez, who was arrested at his home, was charged with unlawfully uploading a copyright work to the Internet, which carries a maximum penalty of three years in prison and a $250,000 fine, the FBI said.
He allegedly used Internet handles such as SkillfulGil.
X-Men Origins: Wolverine, which starred Hugh Jackman and was the latest in a franchise of films based on the X-Men comic books, made $373 million at worldwide box offices.