He was 93.
Raju had been ill for long and his end came at around 7 PM at his native village Chinanindrakolanu in West Godavari district, his colleague and Sarvodaya leader C V Chary said.
Raju's death is a loss to the state in general and the cause of Gandhism in particular, Chary added.
Raju had been MLA for six terms and served as a minister when late P V Narasimha Rao was Chief Minister.
He also set up scores of educational institutions during his lifetime.
Condoling the death of Raju, Chief Minister N Kiran Kumar Reddy recalled the services rendered by him in various fields.