New Delhi: Shiv Menon, the son of Sunanda Pushkar, is being questioned today in connection with her alleged murder.
Mr Menon arrived in Delhi on Wednesday after being summoned by investigators.
A police team has questioned at least 15 people, including Sunanda Pushkar's husband and Congress MP Shashi Tharoor, in connection with the case.
Former Samajwadi Party leader Amar Singh and senior journalist Nalini Singh have also been questioned by police.
52-year-old Sunanda Pushkar was found dead in her suite at a five-star hotel in south Delhi on the night of January 17, 2014, days after she publicly accused Pakistani journalist Mehr Tarar of having an affair with her husband.
Last month, the police registered a case of murder and said Sunanda may have been poisoned.