He was 93.
Singh passed away last evening, his family said.
He had represented Jehanabad parliamentary seat for four terms between 1984 and 1996, besides being a Member of Legislative Assembly (MLA) from Ghosi Assembly seat in the same district during an illustrious political career lasting over four decades.
Mourning the death, Chief Minister Nitish Kumar said Singh was a dedicated and hardworking political leader who gave all his life to social service and welfare of the poor people.
Kumar said that the cremation of the departed leader would be made with state honours.