Sogarath Kapar was asleep when two MRJP cadres fired at his head at 2 a.m. He died on the spot. His wife, Draupati, was also shot in the right thigh when she cried for help.
Kapar, father of four, was an active member of the CPN-UML.
MRJP district member Ganesh Madheshi said Kapar was killed for charging excessive interest on loans from locals.
The District Police Office in Dhanusha is searching for the culprits.
UML cadre survives murder attempt in Bhojpur