The Socialist Party candidate in Mirzapur, Arvind Sen, said that the girl was gang-raped to avenge the poll defeat, allegedly by relatives of a losing candidate.
Her mother was elected for the local government faction, the block development council, in the Mirzapur district of north-east India.
However, a senior police officer told said that a post-mortem report did not find signs of rape.
The latest incident is the latest high-profile case to spotlight women's safety in India in recent years. Two construction workers were arrested for the rape of a woman on the premises of tech giant, Infosys. The men, aged in their 20s, filmed the alleged assault, which occurred on Sunday at one of the IT firm's offices in the western city of Pune in Maharashtra state, officers said.
It comes a week after lawmakers passed a bill allowing harsher punishments for juveniles aged 16-18 following an outcry over the release of a young rapist who served three years in a detention facility for his part in a notorious gang rape in 2012.
Earlier this month, an Indian court sentenced seven men to death after they were convicted of the rape and murder of a Nepalese woman suffering from mental illness, reports said.