New Delhi: The US' Federal Burea of Investigation (FBI) in its report to Delhi police has said that Sunanda Pushkar, the wife of Congress MP and former Union Minister Shashi Tharoor, did not die due to poisoning by polonium or any other radioactive substance.

"We have received the FBI's forensic report by email. A detail report is still awaited. Once we get the full report, the medical board would examine it," Delhi Police chief BS Bassi said on Wednesday, adding, "We could call Shashi Tharoor for questioning."

Delhi police had sought FBI's help in February this year after a panel of doctors from Delhi's AIIMS concluded that the poison could not be detected in Indian labs.

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 Tarar, whom she accused of stalking her husband.

(With inputs from IANS)