The Japan Federation of Bar Associations warned police and prosecutors Wednesday over a case in which a mentally impaired man in Utsunomiya, Tochigi Prefecture, was erroneously arrested and charged for robbery.

The federation warning was issued to the prosecutor general, and to the chiefs of Tochigi Prefectural Police, the Utsunomiya District Public Prosecutor's Office and the National Police Agency.

The federation accused police and prosecutors of seriously infringing on the human rights of the 54-year-old man by forcing him to confess to committing crimes despite knowing he was mentally disabled.

The man was arrested and indicted in 2004 after being suspected of taking about 140,000 yen in two separate robberies in Utsunomiya, in April and May that year.

Another man later confessed to committing the heists and was sentenced to eight years in prison, and the disabled man was acquitted last March by the Utsunomiya District Court.

The federation said investigators disregarded the disabled man's limited mental capacity when they forced him to make confessions.

To prevent similar abuses, the federation proposed that all investigative procedures be taped and recorded when mentally disabled people are questioned.