LJP leader Sudesh Paswan and his brother Sunil Paswan were killed in broad daylight near Tola Dubat in Gaya, about 100 km from here, a district police official said.
Maoists also torched two cars and a motorcycle used in the campaigning in support of the slain LJP leader's wife, who is in the fray for the village head's post.
According to police officials, Maoists left behind pamphlets claiming the LJP leader was punished for being a police informer.
Later, hundreds of local residents protested against the killings by blocking roads and demanding the arrest of those involved in the crime.
Early this week, Maoists slit the throats of three people for allegedly working as police informers.