TOKYO , Japan ( CNN ) -- Death row inmates in Japan spend decades in isolation and face inhuman conditions that can lead to mental illness , Amnesty International said Thursday . Amnesty urged Japan 's new government to improve death row conditions . Some who have exhausted their legal options are not told they will be put to death until the last minute , the human rights group said . Japan executes such prisoners despite signing an international law that requires inmates with serious mental illness to be exempt from the death penalty , according to Amnesty . The report urged the government to establish a moratorium on executions and consider abolishing the death penalty . As many as 102 prisoners face execution in Japan -- many of them elderly inmates who have lived in isolation for decades , the human rights group said . However , the number of death row prisoners suffering from mental illness is unknown . `` The secrecy around the death penalty and prisoners ' health , combined with a lack of scrutiny by independent mental health experts , has led to reliance on secondary testimony and documentation to assess the mental state of those on death row , '' Amnesty said . Japanese officials declined to comment Thursday . The report by the London-based human rights group comes as a new Japanese administration prepares to take over after ousting the long-ruling government in a landslide victory last month . Amnesty urged the new Democratic Party of Japan government , which will form in mid-September , to improve death row conditions . Inmates are especially vulnerable because of their lack of human contact , Amnesty said . Inmates are allowed only visits to restrooms and must remain seated in their cells at all times , without light and fresh air , Amnesty said . `` These inhuman conditions increase a prisoner 's anxiety and anguish , and in many cases push prisoners over the edge and into a state of mental illness , '' said James Welsh , Amnesty International 's health coordinator and lead author of the report . The illness affects prisoners ' ability to take part in the legal process , sometimes leading them to end their appeals , Amnesty said .
Report urged the government to establish a moratorium on executions . As many as 102 prisoners face execution in Japan , Amnesty International says . Number of death row prisoners suffering from mental illness is unknown .