The Federal Bureau of Investigation in the United States sent back its report on the death of Sunanda Pushkar, wife of Congress leader Shashi Tharoor, to the Indian government on Tuesday, and ruled out poisoning from polonium or any other radioactive substance, The Hindu reported. The Indian labs had sent them her visceral samples nine months ago after they suspected the presence of radioactive isotopes that they did not have the facilities to verify. While the reports were unconfirmed, the Delhi Police Commissioner BS Bassi said some facts related to the case would be released soon.

Other than ruling out the radioactive substance angle – the levels were apparently within the safe limits — the report is believed to have pinpointed the poison that caused her death. Once the police know the name of the poison, they can trace how it was procured and administered to Pushkar, which would be a valuable lead in the case. Pushkar’s death, in a five-star hotel in Delhi in January 2014, has been shrouded in mystery.