New Delhi, Dec 21 (IANS): Three people died due to suffocation inside a businessman's house here while another is battling for life in a city hospital, police said Sunday.

Rajesh, 24, Santosh, 33, Munna, 26, and Uday, 45, were found unconscious at the servants' quarter of the businessman's home in Hauj Khas area of south Delhi at around 11.30 a.m.

They were rushed to Max Hospital where Rajesh, Santosh and Munna were declared dead while Uday was stated to be in critical condition.

A police officer said Uday and Rajesh have been working in the house of Sudheer Oberoy, who runs an optical shop in Connaught Place, while Santosh was his driver.

Munna was the friend of one of the victims and had stayed with them in their 10x8 feet room, he said.

The officer said there was a birthday party inside Oberoy's house Saturday night. "All the victims worked till 5 a.m. (Sunday) and then went to sleep."

"During initial inquiry, it came to light that the victims had lit a coal fire inside the room to keep it warm. They died in their sleep due to suffocation," said the officer.

The incident came to light when a woman domestic help found them in an unconscious condition.