A 50-year-old man and his son were arrested for allegedly killing the former's minor niece by administering poison to her for having an affair with a man in Madhya Pradesh's Rajgarh district, police said on Saturday.

Anar Singh Sondhia and his son Piru Singh Sondhia (30) were arrested on Friday under section 302 (murder) and other relevant provisions of the IPC and have been remanded to judicial custody, inspector Mukesh Gaur of Khilchipur police station said.