Sunanda Pushkar, wife of junior human resource development minister Shashi Tharoor, died an "unnatural, sudden death" with her body bearing "injury marks", said a doctor Saturday.
Tharoor was later hospitalised after he complained of chest pain.
Sleuths scanned CCTV footage of the hotel where her body was found and questioned staff while sources told IANS that it could be "a case of drug overdose" and also spoke of a verbal spat between the high profile couple while they were on a flight from Thiruvananthapuram to Delhi.
"We can say that it is a case of unnatural sudden death. There were certain injury marks on the body but we can't divulge details at this point," said Sudhir Gupta, one of the three doctors who performed the autopsy at the All India Institute of Medical Sciences (AIIMS) here.
"We have retrieved some biological samples and have videographed the whole procedure and have taken photos...," he added.
Pushkar, 52, who was quite active in social circuits, was found dead under mysterious circumstances in her room at The Leela Palace hotel in south Delhi Friday. She was cremated in Delhi Saturday evening.
Her death came barely 24 hours after she and Tharoor, 57, a Congress MP from Thiruvananthapuram, declared they were "happily married" following the public airing of tweets that hinted at an extra-marital relationship and alleged involvement of a Pakistani journalist.
For both Tharoor and Pushkar it was their third marriage. Her son is from an earlier marriage.
Sources told IANS: "It could be a case of drug overdose but things would be clear only after the detailed autopsy report" and added that it could be an overdose of sleeping pills.
The couple had a "verbal spat" during their flight from Thiruvananthapuram to Delhi, the sources revealed.
In the hotel too they were arguing, which was disclosed by the housekeeping staff to police during investigation.
"Hotel's housekeeping staff said that the couple were seen arguing in the lobby," police sources told IANS.
Tharoor was admitted in the AIIMS ICU after he complained of chest pain around 3.30 a.m. Saturday and was later shifted to a private ward.
An exhausted looking Tharoor left the hospital in an ambulance around 2.30 p.m after being discharged.
AIIMS spokesperson Amit Gupta said the minister's condition was stable, his ECG was normal and hypertension was the cause of the discomfort.
Pushkar had been treated at a Kerala hospital whose doctors led by G. Vijayaraghavan told reporters Saturday that she did not have any grave illness.
E.M. Najeeb, executive director of KIMS Hospital, where Pushkar was admitted Jan 12, told IANS that he met the couple on numerous occasions in the three days that she was in hospital.
"On 12th night, their friend from Delhi was staying with her at the hospital and the next day Tharoor spent the night with her. On the 14th, she was discharged and doctors had asked her to come back later," said Najeeb.
