Shizuoka District Court decided to "start the retrial over the case" of Iwao Hakamada, 78, who was convicted for the grisly murder of his boss and the man's family, a court official said.
Delivering his ruling, presiding judge Hiroaki Murayama cited possible planting of evidence by investigators to win a conviction as they sought to bring closure to a crime that shocked the country.
"There is possibility that (key pieces of) evidence have been fabricated by investigative bodies," Murayama said in his decision, according to Jiji Press.
The judge also ordered Hakamada's release, saying continued confinement "goes against justice".
AFP