Addressing reporters here, Gandhi said that the investigation is needed as it has constituted a similar probe for Syria and launched an international process to conduct referendum in East Timor, South Sudan.
On India's foreign policy, Gandhi, who is in the city to garner support of like-minded human rights activists, said, "India not consulting its foreign policy with Tamil Nadu is a 'violation' of its federal structure."
The Tamil traditional homeland, mentioned in Indo-Lanka accord, is 100 per cent occupied with the ratio of one armed force for every six Tamils, Gandhi said and charged that the same military had committed 'genocide' against Tamils.
Hence, an international investigation into the "falling" graph of human rights is a must and so is a referendum for Tamil people in Srilanka, he said.