Iwao Hakamada, the longest serving death-row inmate, has insisted for 40 years he is innocent of the four murders he was convicted of. The evidence was suspect, he says, and his confession was coerced.

The judge who wrote the ex-boxer's death sentence has all along also agreed with this position.

"My feelings about Mr. Hakamada remain the same — I believe he is innocent," said Norimichi Kumamoto, who has revealed that he argued for acquittal but was outvoted by two other judges in their secret deliberations before handing down their ruling in 1968. As the junior judge, he was tasked with writing the death sentence order.