Police in the Indian capital Delhi say that they are treating the death of the wife of former Indian minister Shashi Tharoor as murder, nearly a year after her body was found in a hotel room.
Sunanda Pushkar’s death was “not natural and was due to poisoning,” Delhi police chief BS Bassi said.
Initially, doctors said she might have died from an overdose of drugs.
Mr Tharoor, a Congress party MP, married Ms Pushkar, a former Dubai-based businesswoman, in 2010.
Mr Bassi said the police had received a “final report” from the doctors saying that Ms Pushkar was poisoned.
“The poison could have been administered orally or it could have been injected. To proceed further in this matter, we have decided to register a case of murder,” he said.
Medical samples would be sent to foreign laboratories to find out out the “quantity of poison” found in Ms Pushkar’s body.
It is, however, still not clear what poison was given to Ms Pushkar, and how she could have unwittingly or been forced to take it.
There is also no clarity over the motive of the alleged murder.
Asked why it had taken the police nearly a year to treat the death as murder, Mr Bassi said the doctors examining the evidence had sought “additional information” on more than one occasion, and police had provided that.
Ms Pushkar was found dead in a five-star hotel in Delhi on 17 January last year.
The couple had became embroiled in controversy over a series of Twitter messages before Ms Pushkar’s death that appeared to reveal he was having an affair with a Pakistani journalist.
Ms Pushkar and Mr Tharoor later insisted they were happily married and blamed “unauthorised tweets” for causing confusion.
Mr Tharoor has repeatedly called for a swift investigation into the case.
Mr Tharoor, a former UN diplomat, was forced to resign from his first ministerial position in 2010 amid controversy over his involvement in bidding for a cricket team.
Ms Pushkar had allegedly received a free stake in the Indian Premier League franchise he was bidding for.