Three air-conditioner mechanics were found dead while another was in an unconscious state inside a locked house in the Dakshinpuri area of south Delhi on Saturday, police said.
The revelation was made when a police team rushed to the house after it got a call from a person who said his brother was not picking up his phone.
Police found four men unconscious on the first floor of a one-room house.
"They were rushed to Dr Ambedkar Hospital and later shifted to Safdarjung Hospital and AIIMS Trauma Centre, where three of them were declared dead," an officer said.
The fourth man, identified as Haseeb, is undergoing treatment, he said.
The caller, Zishan, a resident of Bhalswa Dairy, told police that his relatives Imran alias Salman, and Mohsin, were among those inside the house.
One of the deceased is yet to be identified.
All four were AC mechanics and had been living together. The exact cause of death is yet to be ascertained.
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