Initiating a debate, Raja asked why the government never took up the issue of "war crime" in Sri Lanka.
"Government of India betrayed Sri Lankan Tamils at a crucial moment," Raja contended in the Rajya Sabha.
"There is a demand for international impartial investigation. So far India has not raised this demand. The European Union has come out with a strong statement," the Communist Party of India (CPI) leader said.
He quoted a report by a committee formed by the UN secretary general to state that more than 40,000 civilians were killed and more than 50,000 went missing as the Sri Lankan military crushed the Tamil Tigers in May 2009.
"What happened in May 2009 was nothing but genocide. We have not seen such genocide in any country in contemporary history," Raja said.
"I do not stand here to condole their death but to demand justice for those who were killed and for those who are alive in Sri Lanka.
"I stand here to demand an impartial international investigation on war crimes and abuse of human rights.”
Raja quoted Sri Lankan President Mahinda Rajapaksa as stating that he was fighting the war for India.
"What the Sri Lankan government told the world, the government of India was a collaborator (in the war against LTTE), what is the meaning of your silence, why you are not speaking?"
Raja asked New Delhi to take up the issue internationally and to establish a mechanism to monitor the aid given to Sri Lanka for the resettlement of war displaced Tamils there.
New Delhi: Communist leader D Raja on Thursday accused the Indian government of betraying the Sri Lankan Tamils at a crucial time by not raising their mass killings in international forums.
First Published: Thursday, August 25, 2011, 15:36