The incident occurred on Sunday night in Anand Lok area.
"The family had gone to attend a marriage around 9 p.m. on Sunday but did not lock the main gate or shut the windows," a senior officer told IANS.
"When the family returned home around 4 a.m., it found the room ransacked."
The servants employed in the house were on the backside and sleeping at the time of the robbery.
"The unlocked gate and windows provided easy passage to the robbers," the officer said. "The robbers targeted only one room and broke the almirah to take away the valuables.
"In their complaint to police, the family has said that diamond jewellery worth Rs 3 crore and Rs 60,000 in cash had been stolen."
