The head of the Shizuoka District Public Prosecutor's Office in central Japan is preparing to apologize in person as early as Wednesday to Iwao Hakamata, an 88-year-old former boxer recently acquitted of a 1966 quadruple murder in a retrial, sources said Thursday.

Hideo Yamada, the chief prosecutor of the office in Shizuoka Prefecture, is expected to visit Hakamata at his home in the city of Hamamatsu.

The chief prosecutor is expected to apologize to the former death row inmate over his prolonged court proceedings.

Last month, prefectural police chief Takayoshi Tsuda apologized directly to Hakamata.

The Shizuoka District Court, in its Sept. 26 retrial ruling, ruled that evidence including Hakamata's confession obtained through coercive interrogation and blood-stained clothes purportedly worn at the time of the crime was "fabricated" by investigators.

The prosecution decided not to appeal against the judgment last month.

Prosecutor-General Naomi Unemoto said then, "We are sorry for placing Hakamata in a legally unstable situation for a long time."