New Delhi, Aug. 23: Thieves broke into a bungalow in south Delhi's Defence Colony on Sunday night and decamped with diamond jewellery worth Rs 3 crore and Rs 60,000 in cash in one of the biggest burglaries in the capital in recent memory.

The bungalow belonged to Tanmay Seth, the son-in-law of Jet Airways vice-president (security) Avneet Singh. Seth had gone out with his family for a wedding.

"When they returned home at midnight, they were shocked to find the main door broken open. Seth immediately alerted the local police station," said Nupur Prasad, additional DCP (south).

A preliminary probe has suggested that the thieves could have entered through one of the windows left open.

A police officer said three domestic helps were asleep inside the house at the time of the burglary. "They are being questioned."