New Delhi, Sept. 23 -- A 65-year-old woman was found dead in a decomposed state and her 70-year-old husband, a retired music teacher, was lying critically ill beside her in their Jamia Nagar flat late Sunday night, after police broke into the locked home after frantic calls from relatives who had been unable to reach the couple for days. Their 50-year-old son, described by police as "mentally challenged" and with a history of psychiatric illness, was found sitting outside the bedroom and later taken to the Institute of Human Behaviour and Allied Sciences (IHBAS). Police said the incident came to light when a PCR call was received around 11.30pm on Sunday, from the woman's brother and sister-in-law, saying they had been alerted by the couple's daughter in Hong Kong after failing to contact her parents for nearly a week. When these relatives tried to enter the home on Sunday, the son allegedly refused to open the door. "Seeing the case's sensitivity, the SHO and ACP rushed to the spot where the family members were present. The door was found locked from inside. We broke open the door to get inside. In one of the bedrooms, we found a dead body on the bed and her husband was found lying to her. He was in a critical and fragile condition. The staff rushed him to AIIMS as he needed medical care. Their son was sitting outside the bedroom," said Hemant Tiwari, DCP (southeast). Police said the couple lived in Queen Apartments in Jamia Nagar. The man, a retired music teacher at a school nearby, remains hospitalised in fragile condition, said the DCP. His wife's body was sent for autopsy, with police noting it bore no external injuries but was "highly decomposed," indicating she may have died several days ago. Doctors told police the death appeared to be natural, though the exact cause will be determined after post-mortem....