The deceased have been identified as Rajan Basnet (27), his wife Pavita and their seven-month-old daughter Srijana. According to police, the family originally from Bamdi in Ramechhap had been living in Birendra Chock since last year. Basnet, an army man deputed in Chitwan, was in the Capital to attend training at the Army Headquarters.

DSP Dan Bahadur Karki, chief at the Metropolitan Police Circle New Baneshwor, said preliminary investigation showed that the trio had died of carbon monoxide poisoning as the family had burnt charcoal in the cramped bedroom to ward off cold.

“There was no ventilation in the room while the only window was closed,” said Karki. As the family did not open the door till 10am, the house owner informed the police about it. When the police broke open the door, the three were lying dead on the bed. The couple had burnt a briquette in the room to keep the child warn overnight. The bodies have been taken to Tribhuvan University Teaching Hospital for post-mortem.

According to police, such deaths are reported in the Capital in small numbers every year. Burning coal or briquettes in an enclosed space enables the concentration of carbon monoxide, a gas released during incomplete combustion.