Pushkar died within about three years of her marriage with Tharoor.
His party Congress was heavily defeated in 2014 by Prime Minister Narendra Modi's Bharatiya Janata Party. Even after years, the Delhi Police had not arrested anyone and no custodial interrogation took place, Swamy had said, adding that the post-mortem examination report confirmed Sunanda's death was "unnatural" and "due to poison". He also raised a question on the investigation method and motives of the Delhi Police that if this is the result after investigating for more than four years, then the method of investigation is questionable.
On Twitter, Tharoor called the chargesheet, which the court will consider on May 24, "preposterous", stressing that he will contest it "vigorously".
Mr Tharoor himself termed the charge sheet as "preposterous" and said he intends to contest it "vigorously".
Congress sources conceded that the almost 3,000-page charge sheet that the Delhi Police had filed in the Metropolitan Magistrate Court, naming Tharoor as the only person as accused in the case, was inevitable as Sunanda had died within seven years of her marriage with the leader. The couple allegedly had a disagreement on a flight from Kerala to Delhi. The IO urged the court to summon Tharoor, the Lok Sabha MP from Thiruvananthapuram, as an accused as the investigation is yet to be completed in the case.
Police, however, maintained the charges against Tharoor were finalised on the basis of "medico-legal and forensic evidence", the newspaper said. The agency while asking the court to take cognizance of the charge sheet said there was enough evidence to proceed against Tharoor. "It is coming from the BJP headquarters...it is coming from the factory of lies".
The political heat in the case increased when the central Govt changed from Congress-led UPA to BJP-led NDA. The body was reported to have borne marks of injuries, but an autopsy determined that the cause of death was an overdose of sedatives and other medication. She was undergoing medical treatment at the time of her death.
He also said there was no statement of any witness or family member of the deceased.