Burglars broke into four houses of a high security Delhi Police apartment complex in Mayur Vihar in east Delhi and decamped with cash and jewellery.
As the owner of the houses are out of town, the police was unable to calculate the burgled amount.
However, the fact that the burglers knew that the owners were away has made the police suspect that it is an insider's handiwork.
The matter came to light on Thursday when one of the owners returned and found his house ransacked, the police said.
"The owner of the house is a retired police officer but currently a woman lives there, who works in a media organisation. She had gone to Bangalore a few days ago. The occupants of the other three houses haven't returned yet," a police officer said.
A case of burglary has been registered at the Mayur Vihar police station and further investigations are on.