Sunanda Pushkar, wife of Congress MP Union minister Shashi Tharoor, did not die of poisoning from plutonium or any other radioactive substance, an FBI lab report has reportedly said.

Sources told The Hindu that the reports have indicated that radiation substances in her body had not reached toxic levels and could not have caused her death.

Doctors from AIIMS, who had confirmed poisoning as the reason behind Pushkar's death, had not named the poison. They had however mentioned some poisons, most of which were radioactive isotopes, and said that Indian labs did not have the facilities to identify the poison which caused her death.

The FBI lab reports mention the name of the poison and Delhi Police Commissioner B.S. Bassi told The Hindu that "some facts related to the case" would be disclosed soon.

The Hindu report further states, "The name of the poison would now lead the Special Investigating Team, which is probing the alleged murder, to how it was procured and administered into Sunanda's body."

Sunanda Pushkar was found dead in a luxury hotel in Delhi on January 17, 2014. Of the several theories surrounding the cause of her death doing the rounds, one of them was plutonium poisoning.