The acquittal of former presidents of West Japan Railway Co. over a tragic 2005 train derailment has prompted calls for legal reforms that would enable prosecutors to hold corporations criminally liable for causing large-scale accidents.

The Supreme Court on Monday upheld a lower court's decision that three former heads of JR West were not guilty of negligence over the accident that killed 106 passengers and the driver in Amagasaki, Hyogo Prefecture.

"The decision showed that judicial authorities did not fulfill their role at all," said Shigemi Omori whose daughter was killed in the accident.