Sukhdool Singh aka Sukha Duneke, a Sikh leader campaigning for Khalistan, was shot dead in Winnipeg, Canada.
Singh was wanted by the Indian government as the Indian agency, NIA, had issued warrants against him.
The killing comes days after Canadian Prime Minister Justin Trudeau accused India of killing Sikh leader Hardeep Singh Nijjar in June this year.
Trudeau said in parliament on Monday that Canadian intelligence agencies have found a “credible” link between his death and the Indian state.
The prime minister stated that he discussed Najjar’s murder with Indian Prime Minister Narendra Modi during the recent G20 summit in New Delhi.
“Any foreign government’s involvement in the killing of a Canadian citizen on Canadian soil is an unacceptable violation of our sovereignty,” he told lawmakers.
“It is contrary to the fundamental rules by which free, open, and democratic societies conduct themselves.”
Pavan Kumar Rai, an Indian diplomat, was expelled from Canada on Monday, according to Canadian Foreign Minister Melanie Joly.
Mr Nijjar was shot dead in his vehicle on June 18 in the popular car park outside the Guru Nanak Sikh Gurdwara in Surrey, British Columbia, by two masked individuals.
In a tit-for-tat move, India later dismissed a Canadian diplomat.
The Canadian government issued a travel alert the day before, advising its citizens to exercise extreme caution in India owing to the possibility of terrorist strikes across the country.
