A 57-year-old assistant commissioner of police (ACP) allegedly shot dead his wife and nephew with a gun before shooting himself fatally at his home in Maharashtra's Pune city on Monday, an official said.

The incident took place at around 3.30 am at ACP Bharat Gaikwad's bungalow in Baner area. The reason behind the incident was yet to be ascertained, the official from Chaturshringi police station said.