Police investigating Sunanda Pushkar's mysterious death on Friday night questioned a number of hotel staff and checked the CCTV footage of the lobby of the third floor of the luxury hotel where she was staying.
Sources in police said call details record of Pushkar was also being checked as part of the probe into her death.
A team of Central Forensic Science Laboratory reached the hotel around 10:30 PM and immediately swung into action.
Pushkar was found dead inside the suite no 345 in the Leela Palace hotel where she and her Minister husband Shashi Tharoor had checked in on Thursday.
Investigators said they are screening the call details record of Pushkar as well as her tweets in the last few days.
They said a number of hotel staff, including those who had gone to the suite, were being questioned to corroborate the version of Tharoor and his staff.
The police is also searching the suite thoroughly to see whether Pushkar had used any medicine, they said.
The minister's private secretary, Abhinav Kumar is said to have telephoned the police control room around 2100 hours after which personnel from Sarojini Nagar police station rushed to the hotel in a posh area of South Delhi.
Police sources speaking on condition of anonymity said they suspect it could be a case of suicide.
Kumar said Pushkar was a little unwell Thursday morning.
Pushkar and Tharoor were at the centre of a raging controversy in the last two days when reports emerged that she was upset over reported text and tweet messages between her husband and Mehr Tarar, a Pakistani journalist.
A joint statement from the couple on Thursday said that they were "happily married" but distressed by "some unauthorised tweets".