Wardens at Nagoya Prison tore up and threw away an inmate's written petitions to the justice minister that revealed violence at the facility, according to a complaint submitted to prosecutors by the former inmate.
Five officials of the prison are under arrest for allegedly abusing a prisoner with restraining devices.
According to the complaint, filed Friday by the 37-year-old former prisoner against several officials at the prison, the petitions revealed that the guards had attacked him and other inmates in October 2000. Justice Minister Mayumi Moriyama later rejected the claim on the grounds that she could not confirm the attacks had taken place.
The complaint said the man continued to be abused and he tried to submit petitions until he was released from the prison in July this year. Each time, they were torn up in front of him by the guards and thrown away.
The guards also threw away other documents and papers, including notebooks recording acts of violence in the prison, it said.
The man told his lawyers that his hopes of improving conditions in the prison had been dashed.