New Delhi: The Sunanda Pushkar murder case took an ugly turn on Tuesday with BJP leader Subramanian Swamy and Congress MP Shashi Tharoor indulging in a war of words. While Swamy clearly stated that Sunanda's husband Tharoor was a part of the murder conspiracy, the former Union minister hit back by daring the BJP leader to name the murderer if he knew who he was.Adding to the strings of accusations against Tharoor, Swamy challenged Tharoor to reveal the identity of the 'killer' to the police. He told CNN-IBN that he had never stated that he knew who the murderer was. He clarified that he had just said that Tharoor knew who Sunanda's murderer was.

Swamy clearly stated that Tharoor was a part of the murder conspiracy and said if he had known the killer he would have told the police long ago. "I have been proved right that Sunanda was murdered. Thaoor has been telling lies. Tharoor needs to be watched. He should be questioned and if he lies he should be taken into custody," he said.

Swamy further said, "He should be questioned and if he was to lie to the police then he should be arrested. This action should be taken soon as an FIR has already been registered for murder."

The BJP leader also accused Tharoor of trying to cover up his wife's murder as a natural death. Swamy claimed that Sunanda was put to death as she had wanted to tell the truth about the dubious dealings in the IPL.

Responding to the accusations, Tharoor at the Delhi airport said, "If Subramanian Swamy knows the murderer then let him tell the police."

Speaking on behalf of Tharoor, C Rajeshekhran said the murder FIR was filed all of a sudden. "The medical report does not say that murder case has to be registered. Why is the report coming after so many days? The police did not do its duty properly. Why did the police not act for so many days? he said.

On Monday, Delhi Police Commissioner BS Bassi had said the Congress leader was soon to be questioned in connection with his wife's murder. He also mentioned that the SIT had been asked to fast-track the case so that a charge-sheet could be filed at the latest.

The Delhi Police had earlier this month filed a murder case in connection with Sunanda's death under section 302 of IPC on the basis of an AIIMS medical report that stated that her death was unnatural and was due to poisoning.

Bassi said Pakistani journalist Mehr Tarar, whose friendship with Tharoor had reportedly led to a row between him and Pushkar, may also be questioned if needed.

Sources added that there was a bite mark on the left hand of 51-year-old Sunanda and several blue colour contusions on her right hand. She was found dead in a luxury hotel in Delhi on January 17, 2014.