MDMK chief Vaiko, along with two pro-Tamil advocates, had challenged the ban that was earlier upheld by the Unlawful Activities Tribunal in Chennai. Mr Vaiko, who had fought the case himself in courts, had contended that the LTTE's objective of establishing a sovereign nation for Tamils in the island did not pose any threat to the territorial integrity of India, so a ban here was unlawful.
Mr Vaiko has also challenged the extension of ban. "I would continue to fight; the basis of the ban would crumble," he said.
In May 2009, the Sri Lankan military defeated the LTTE or Tamil Tigers and ended a nearly two-decade-long civil war in the island. Human rights activists have accused the defence forces of war crimes and atrocities against civilians.