Swamy has alleged that "inordinate delay" has been caused in the investigation "which is a blot on the justice system".
He has sought a court-monitored investigation by setting up of a multi-disciplinary SIT consisting of Intelligence Bureau, Enforcement Directorate, RAW, Delhi Police and headed by the CBI in the case.
Pushkar was found dead in a suite of a five-star hotel in south Delhi here on the night of January 17, 2014.
It said "the fact that influential political personalities and their henchmen are involved in this case presents an added dimension to the issue and raises questions on the efficacy of the existing systems and practices to counter the moves of such influential persons facing serious criminal charges."
In May this year, after a newly-launched TV channel aired a news relating to Pushkar's death, Tharoor had filed a civil defamation suit against the channel's managing director in the High Court claiming damages and compensation of Rs two crore for allegedly making defamatory remarks towards him.
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