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Mr Tharoor accused Mr Achuthanandan of making politically motivated demands for a case against him. "Let us all encourage Mr Achuthanandan to go and ask the Delhi police, not the Congress, for a case. The investigations are not being conducted by the Congress. There is no FIR, charge-sheet or complaint against me," the Congress MP said.
In response, Mr Achuthanandan told NDTV that his allegations were based on "legal procedures". Slamming the Congress for "inaction", he said his comments were not politically motivated. "The law says that if a woman dies within seven years of her marriage, in such circumstances, there has to be a case registered. Why has there not been any case yet when there were even wounds found on Sunanda Pushkar Tharoor's body?" Mr Achuthanandan told NDTV.
Mr Tharoor on Wednesday complained to the Election Commission against Left and BJP leaders for what he called a "sustained campaign of vilification and defamation."
Based on his complaint, the state administration issued notice to CPI-M leader M Vijayakumar, who allegedly said at a public meeting on Tuesday that "Shashi Tharoor has a PhD in violence against women."
Mr Vijayakumar and CPI legislator VS Sunil Kumar, who reportedly called the Congress MP a "murderer" in a TV interview on Monday, were asked to explain their remarks by Saturday.
Mr Tharoor has also complained about "defamatory" hoardings by BJP's women activists showing him being beaten by women protesters.
"This is a sustained campaign by both the Left Democratic Front and the BJP, intended to portray me as someone who harms women, and using false stories about the tragic death of my wife to assassinate my character," the Congress leader said.
52-year-old Sunanda was found dead at a five-star hotel in Delhi on January 17, days after a public spat with a woman she suspected was having an affair with Mr Tharoor.
An autopsy report found that she died of poisoning. Doctors who handled her post-mortem described her death as "sudden and unnatural" but the police are yet to confirm how she died, as a forensic report has not been released till now.
Mr Tharoor, 58, is fighting for re-election in Thiruvananthapuram in Kerala, the constituency from where he won his first election in 2009.
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