The AIIMS doctor's body which was asked to give its opinion on the FBI viscera report on the possible cause of Sunanda Pushkar's death on Friday said overdose of an anti-anxiety drug killed her. "Sunanda Pushkar died of Alprazolam overdose," the board said.

India Today said that the AIIMS report slammed the FSL and CFSL over their failure to detect poisoning in Sunanda's body.

The Special Investigation Team (SIT), which is probing the Sunanda Pushkar case, may question Sunanda's husband and Congress leader Shashi Tharoor once again after Delhi Police on Friday received AIIMS medical board's report in the case.Delhi Police chief BS Bassi on Friday said, "The medical board report has been received and merits shall be ensured in the case".

Sunanda Pushkar's samples were sent to the US for testing after traces of radioactive isotopes were found in her body during the post-mortem examination. The eight-page FBI report, received around nine months after the samples were sent for examination, had ruled out radiation poisoning in Sunanda's case.

The investigators have so far conducted polygraph test on six persons, all prime witnesses in the case, including Tharoors' domestic help Narayan Singh, driver Bajrangi and Sanjay Dewan, a close friend of the couple.

Tharoor was not subjected to the test but was questioned.Pushkar, who married Tharoor in 2010, was found dead under mysterious circumstances inside a room at the Leela Palace Hotel in Delhi on January 17, 2014. Police registered a murder case on January 1, 2015.Prior to her death, Pushkar was embroiled in a spat with Pakistani journalist Mehr Tarar, whom she accused of stalking her husband.