Anand Tripathi (35) and his son Ashish (12) were found dead in their house, after which an FIR was registered against three policemen, they said.
Tripathi had filed a case in a court seeking registration of a case of loot and manhandling against the three policemen, who, his family alleged, killed him and his son.
The family members alleged the policemen had been threatening Tripathi to withdraw the case against them.