He was 56.
Sardar represented Potka Assembly constituency from 2005 to 2010.
JMM Senior Vice-President Champai Soren, who visited Sardar's home to pay his homage, said he played a major role in the statehood movement of Jharkhand.
Soren said Sardar's death was an irreparable loss to the party as he was instrumental in increasing JMM's base in rural pockets of East Singhbhum district.