TOKYO » A Japanese court on Thursday ordered the release of the world’s longest-serving death row inmate, saying investigators had likely fabricated evidence and ordering a retrial in a murder case that left the man behind bars for nearly half a century.

The Shizuoka District Court suspended the death sentence for 78-year-old Iwao Hakamada, a former professional boxer convicted in the 1966 murder of a family. More than 45 of the 48 years he has spent in jail have been on death row, making Hakamada the longest-serving such inmate, according to Guinness World Records.

Hakamada was sentenced to death in 1968, but was not executed because of a lengthy appeals process. It took 27 years for the Supreme Court to deny his first appeal for a retrial. He filed a second appeal in 2008, and the court finally ruled in his favor on Thursday.

The court said DNA analysis obtained by Hakamada’s lawyers suggested that investigators had fabricated evidence. It ordered a retrial in the case, making Hakamada only the six death row inmate to get a retrial in Japan’s history of postwar criminal justice. Four of the previous inmates were acquitted in their retrials, while the fifth case is still pending.

Thursday’s ruling underscores Japan’s much-criticized closed interrogations, which rely heavily on self-confession. Hakamada had confessed in a closed interrogation.

Hakamada was convicted of killing a company manager and his family and setting fire to their central Japan home, where he was a live-in employee.