Bale, currently co-starring in the boxing drama "The Fighter," will portray an American priest in the movie, which is expected to start filming in Nanjing on Jan. 10, the Chinese director told reporters Wednesday. The film is an adaptation of a Chinese-language novel by contemporary writer Yan Geling about 13 sex workers in Nanjing who volunteered to replace university students as escorts for invading Japanese soldiers. In the novel, the American priest presides over a Catholic church that shelters a group of prostitutes and young female students during the invasion.

Historians say the massacre, known in the West as the "Rape of Nanking," resulted in the slaughter of at least 150,000 civilians. China puts the number killed at 300,000, making it one of the worst atrocities of the WWII era.

Bale was picked because of his versatility and dedication to his roles, Zhang said, noting he was impressed by the research Bale did into the history of the massacre.