Police investigating Sunanda Pushkar's death mysterious death on Friday night questioned a number of hotel staff and checked the CCTV fotage 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 (CFSL) 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 Tharooor 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 yesterday 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 yesterday said that they were "happily married" but distressed by "some unauthorised tweets".
Pushkar had accused Tarar of "stalking" her husband and trying to "break" her marriage when she was away for medical treatment.
She had told couple of newspapers that she was considering divorce from Tharoor in the wake of the alleged extra-marital affair.
Late last night, Pushkar had tweeted that the Pakistani journalist was "lying".
The Pakistani journalist rubbished the charges of having any relationship with Tharoor who is Congress Lok Sabha MP from Thiruvananthapuram.
After Pushkar's death Tarar, tweeted: "I just woke up and read this. I'm absolutely shocked. This is too awful for words. So tragic I don't know what to say. Rest in peace, Sunanda."
In another tweet she said "What the hell. Sunanda. Oh my God."
Kumar said Tharoor and Pushkar were staying at the hotel since Thursday because of some painting works at their home.
Asked about the cause of death, Delhi Police spokesperson Rajan Bhagat said there is no apparent sign which can reveal that.
On when the post mortem would be conducted, he said a decision on it will be taken under the supervision of the SDM doing the inquest proceedings.