New Delhi: While Delhi Police crime branch was about to lodge an FIR on the death of late Narayan Dutt Tiwari’s son Rohit Shekhar, the post-mortem report of the politician's son who had struggled to prove Tiwari had sired him, says he was smothered to death with a pillow.

Rohit Shekhar's death was caused by asphyxia, said forensic doctors of the All India Institute of Medical Sciences (AIIMS) who added that the asphyxiation was caused by smothering.

The Delhi police at a meeting at its ITO headquarters on Friday expressed suspicions regarding Rohit’s death, ostensibly due to a heart attack, and the case was consequently given to the crime branch.

Sources said that Rohit, who did not enjoy good relations with his wife, died shortly before the second anniversary of their marriage. A police team is taking stock of Sharma’ house and collecting evidence.

The police are expected to soon question his wife and his mother in connection with his death. His close servant Bholu Mandal too has been made to furnish a detailed statement to the police.

The crime branch team is also taking a close look at the photographs from Rohit’s house and the CCTV footage from there.

The police are expected to register an FIR Friday evening and then formally record the statement of concerned persons.

Rohit, son of former chief minister of Uttar Pradesh and Uttarakhand, ND Tiwari, was brought dead to Delhi's Max Saket hospital.

DCP South Delhi Vijay Kumar issued a statement to confirm the death. He said, "Rohit Shekhar Tiwari, son of late former Uttar Pradesh and Uttarakhand CM ND Tiwari, has been brought dead to Max Saket hospital."

The 39-year-old was resident of Delhi's Defence Colony area, and had fought a long paternity battle with his father for recognition as his son. ND Tiwari had refused to accept him as his son. In 2007, Rohit had filed a paternity suit and in 2014 won the case in the Delhi high court. Later, ND Tiwari had married Ujjwala Tiwari, Rohit’s mother, in Lucknow.