The Delhi Police has registered a murder case in connection with the death of Rohit Shekhar Tiwari, son of ex-Uttrakhand chief minister late N D Tiwari, in the wake of an autopsy report which reportedly stated that Rohit, 40, died of “asphyxia” as he was strangulated and smothered.

The investigation has been transferred to the Crime Branch of Delhi Police, which has registered a case of murder under Section 302 of IPC against unknown persons following the post mortem report.

The autopsy on Rohit’s body was conducted by a medical board comprising five senior doctors of the All India Institute of Medical Sciences (AIIMS). “The medical board unanimously concluded that the cause of death in this case is asphyxia as a result of strangulation and smothering. It is a sudden unnatural death, placed in the category of homicide,” said the head of the AIIMS’ forensic department, Dr Sudhir Gupta.

A resident of South Delhi’s Defence Colony, Rohit had died on 16 April. He was then “brought dead” to Max Hospital in Saket in South Delhi, according to both the police and the hospital authorities. His mother Ujjwala Tiwari, who was admitted to the same hospital for her treatment, had then reportedly received a call from her house about her son being “unwell and bleeding from the nose”. An ambulance had subsequently brought Rohit to the hospital where he was declared brought dead.

Crime Branch officials along with a forensics team of Delhi Police visited Rohit’s house on Friday and questioned his family members and domestic helps.

There are seven CCTV cameras, including two non-functional ones, in Rohit’s house, police said. Rohit had gone to Uttarakhand to cast his vote on 12 April and had returned on the15 April night. He was found ~ on CCTV footage ~ taking support of the wall while walking in an inebriated state, police sources said. He slept till next day evening and no one tried to wake him up. He was found dead with blood oozing out of his nose on 16 April evening, police added.

Rohit Shekhar had fought a six-year-long battle in courts to prove that he was N D Tiwari’s son. The vetarn Congress leader, who died at the age of 93 last year, had initially refused to give his blood sample for a DNA test in this regard. In 2014, the Delhi High Court declared N D Tiwari as Rohit Shekhar’s biological father. The Congress veteran later accepted him as his son.

Rohit had reportedly joined the BJP ahead of the 2017 Uttarakhand Assembly polls and had recently indicated that he could join the Congress.