Manuel Arenas, 58, is alleged to have shot his brother Roman, 56, who had just beaten Manuel's daughter to be chairman of the central Philippine village of Manapao, the Philippine Daily Inquirer reported Tuesday.
Manuel Arenas also lost his bid to be a village councilor.
Police chief Inspector William Limjuco said Manuel Arenas first shot his brother, then his sisters, who were having coffee at a neighbor's house.
The motive for the killings is not known, but Limjuco said investigators believe it may involve political rivalry and a dispute among the siblings over their inheritance.
A task force has been formed to track down Arenas and investigate the deaths.