Citing terror threats from the outfit, Canada has banned the World Tamil Movement and freezed its assets.
"We want to make sure any group who would help terrorist organisations is prevented from doing that," said Public Safety Minister Stockwell Day.
The minister said that the World Tamil Movement was "the leading front organisation for the Liberation Tigers of Tamil Eelam (LTTE) in Canada".
Two months ago, the federal police sought court nod to seize the WTM's bank accounts.
The Toronto-based Sri Lanka United Association of Canada welcomed the government decision to outlaw the group while organizers of the movement describe the organization as a community services agency that focuses on settlement assistance, Tamil education and community development, with offices around the world.
Reports indicate Sitha Sittampalam, the movement's Toronto president since 2004, said he would consult a lawyer about how to proceed with an appeal of the decision. He refused to comment further.