Tharoor's questioning, which started around 8 PM ended around midnight. He left in his vehicle without responding to questions from waiting media. Police too refused to divulge any details of what transpired during the questioning.
Police sources said that this was the first round of questioning and Tharoor may be called again.
However, sources said that the former union minister was asked about the 15 injuries on her body, especially injury number ten which was an injection mark as the medical report has indicated that the poison which caused her death could have either been taken orally or injected.
He was also asked about the reason of the tiff the couple had on the flight from Thiruvananthapuram to Delhi on January 15 following which she left him at the airport and checked in at Leela Hotel.
Tharoor was asked whether Sunanda was suffering from any disease and the kind of medication she was taking. He was quizzed about the empty Alprax tablets which were found in the hotel room and who used to consume it as the viscera tests were found negative for it.
He was queried whether she was suffering from Lupus (a kind of skin disorder) as was speculated.
A visibly glum Tharoor faced searching questions nearly three weeks after a case of murder was registered on the basis of a medical report that concluded that she died of poisoning.
This is for the first time Tharoor has been questioned on death of 52-year-old Sunanda by the police. He was earlier examined by the SDM who was carrying out an inquest proceeding in the case. She was found dead at a luxury hotel on January 17 last year.
A five-member Special Investigation team comprises DCP(South) Prem Nath, Additional DCP PS Kushwah besides three officers.
Tharoor, donning a blue shirt and a black jacket, reached the office of Anti Auto Theft Squad (AATS) in South Delhi's Vasant Vihar area. Tharoor was issued a notice by SIT to join the investigation.
The Congress MP had a meeting with his lawyers at his residence in Lodhi Estate before proceeding to SIT's temporary office which has been heavily barricaded to keep a waiting media at bay.