The deputy head of police of Russia's southern Samara region and five members of his family were found dead in a village house on Sunday, TASS news agency reported.
The 49-year-old Andrei Gosht and his relatives were found with multiple wounds of different types in a house in the village of Ivashevka.
Investigators have yet to comment on a possible motive.
A seven-year old girl was found alive in the house and taken to hospital with head and other wounds. She is now in a coma, TASS cited regional officials as saying.
According to local media reports, the house is owned by Gosht's parents.
Gosht was formerly head of police in Syzran, the third largest city in the Samara region, based on Volga river about 750 km (466 miles) from Moscow.