New Delhi, Feb 05 (ANI): Sunanda Pushkar's son Shiv Menon is being interrogated by the Special Investigation Team (SIT) of the Delhi Police on Thursday in connection with the probe related to her death in January last year. Police Commissioner BS Bassi said Menon's interrogation can throw light on various aspects which can help with the investigation. Sunanda's husband and Congress leader Shashi Tharoor, television journalist Nalini Singh and former Samajwadi Party leader Amar Singh have been interrogated by the SIT so far. Earlier last month, the police had said that 51-year-old Sunanda was poisoned. A case of murder was registered on January 6. Sunanda, who was found dead in the five-star Leela Hotel in Delhi on January 17, 2014, was married to Tharoor for a little less than four years.