NEW DELHI - Ms Sunanda Pushkar, wife of Indian minister Shashi Tharoor, may have died of a drug overdose, a panel of doctors has reportedly concluded.

Reports in the Indian media said doctors have found traces of anti-depressants in her system, however, there was no trace of alcohol in her blood.

Some physical injuries on her body are believed to be unrelated to her death, sources say, NDTV reported, adding that investigations will now focus on whether the fatal overdose was accidental or not.

The final autopsy report was handed to a magistrate looking into Ms Pushkar's death by a team of three doctors from the All

India Institute of Medical Sciences (AIIMS) on Monday, but its details were not made public.

Ms Pushkar, 52, was found dead in a luxury hotel room in New Delhi two days after sending tweets that suggested her husband was having an affair with a Pakistan-based journalist.

Mr Tharoor, in the meanwhile, has testified before a magistrate who is leading the inquest into the death Ms Pushkar.

The 57-year-old high-flying former UN diplomat has called for a quick investigation into his wife's death, saying he hoped this would put an end to rumours about their personal lives.

The case has become an election-year political embarrassment for the ruling Congress party.

"I have finally had a chance to catch up with media reports and am horrified to read the reckless speculation rampant there," Mr Tharoor, a junior human resource development minister, wrote in a letter to Home Minister Sushil Kumar Shinde on Sunday, Reuters reported.

"I pledge my full and unstinting cooperation. Nothing short of truth will end the indignity to which my wife and I are being subjected."

On Monday, Home Minister Sushilkumar Shinde asked the police to conduct an expeditious probe into the death.

"He (Tharoor) has written to me and sought an expeditious probe. I have already talked to the persons concerned and they are doing it," he told reporters on the sidelines of a function in New Delhi.