Earlier this week, Sunanda's 21-year-old son from a previous marriage, Shiv Menon, had released a statement to the media saying his mother was "too strong" to commit suicide and she died due to an "unfortunate combination of media stress, tensions and a wrong mix of different medication".
He asserted that he did not believe that there was a foul play in his mother's death, saying both Tharoor and his mother were "very much in love" despite their "occasional differences" and that he did not believe the Union minister was capable of harming her physically.
On Tuesday, a sub-divisional magistrate, who probed the case, had directed Delhi Police to investigate the murder or suicide angles in the case while concluding that "poisoning" was the cause of her death.
The autopsy report had mentioned more than a dozen injury marks on Sunanda's body besides a "deep teeth bite" on the edge of her left palm.
The Crime Branch team probing the case has decided to go for advanced forensic tests to determine cause of injuries on her body.
The autopsy report had mentioned use of blunt force for the injury marks on both her hands and left cheek.