TOKYO: A man believed to be the world’s longest-serving death row inmate walked free from jail on Thursday after decades in solitary confinement, in a rare about-face for Japan’s rigid justice system.

A slightly unsteady-looking Iwao Hakamada, 78, emerged from the Tokyo prison with his campaigning sister after Shizuoka District Court in central Japan ordered a fresh trial over the grisly 1966 murder of his boss and the man’s family.

Presiding judge Hiroaki Murayama said he was concerned that investigators could have planted evidence to win a conviction almost half a century ago as they sought to bring closure to a crime that had shocked the country.

“There is a possibility that (key pieces of) evidence have been fabricated by investigative bodies,” Murayama said in his ruling.

Shizuoka prosecutors, who have three days to appeal the decision, told Japanese media that the court’s decision was “unexpected”.

Apart from the United States, Japan is the only major industrialised democracy to carry out capital punishment, a practice that has led to repeated protests from European governments and human rights groups, who say the justice system is heavily skewed in prosecutors’ favour.

Hakamada is the sixth person since the end of World War II to receive a retrial after having a death sentence confirmed, and his case will bolster opponents of capital punishment.