A Japanese police chief has apologised in person to 88-year-old Iwao Hakamada after he was kept on death row for more than 50 years until last month, when he was acquitted in a retrial.

Mr Hakamada, a former boxer, was acquitted by the Shizuoka District Court, which said police and prosecutors had collaborated to fabricate and plant evidence against him, and forced him to confess after violent interrogations.

The acquittal was finalised earlier this month when the prosecution waived its right to appeal – though it complained about the ruling – ending Mr Hakamada’s near 60-year legal battle to prove his innocence.

Shizuoka Prefectural Police chief Takayoshi Tsuda visited Mr Hakamada at his home and offered an apology in person. As he entered the room where Mr Hakamada, his sister Hideko Hakamada and their supporter waited, Mr Hakamada silently rose from his sofa to greet him.

Mr Tsuda said, as he stood straight in front of Mr Hakamada and bowed deeply: “We are sorry to have caused you unspeakable mental distress and burden for as long as 58 years from the time of the arrest until the acquittal was finalised.

“We are terribly sorry.”

Mr Tsuda promised a “meticulous and appropriate investigation”.

Japan Death Row Acquittal
Iwao Hakamada now lives with his sister in Hamamatsu, Shizuoka prefecture, central Japan (Kyodo News via AP)

Mr Hakamada, who has difficulty carrying out conversation due to his mental condition from the decades of death row confinement, responded: “What it means to have the authority … Once you have the power, you’re not supposed to grumble.”

Mr Hakamada’s 91-year-old sister, who had stood by her brother through the long process to clear his name and now lives with him, thanked the police chief for visiting them.

“There is no use complaining to him after all these years. He was not involved in the case and he only came here as his duty,” she told reporters afterwards.

“But I still accepted his visit just because I wanted (my brother) to have a clear break from his past as a death row inmate.”

Mr Hakamada was arrested in August 1966 after the killing of an executive at a miso bean paste company and three of his family members in Hamamatsu, central Japan. He was initially sentenced to death in a 1968 district court ruling but was not executed because of the lengthy appeal and retrial process in Japan.

It took nearly three decades for the Supreme Court to deny his first appeal for a retrial. His second appeal for a retrial, filed by his sister in 2008, was granted in 2014.

The court ordered his release from his death row solitary cell but without removing his conviction, pending the retrial process.

Mr Hakamada was the world’s longest-serving death row prisoner and only the fifth death row inmate to be acquitted in a retrial in post-war Japan, where criminal trials take years and retrials are extremely rare.

His case and acquittal have triggered calls for more transparency in the investigation, legal changes to lower hurdles for a retrial, as well as debate over the death penalty in Japan.