Canada has expelled an Indian diplomat and Prime Minister Justin Trudeau is demanding the Indian government co-operate following what Trudeau calls "credible" intelligence linking the government's agents to the shooting death of a British Columbia Sikh leader. 

Harjit Singh Nijjar was shot in the parking lot of his gurdwara in Surrey, B.C., on June 18. While Sikh community leaders in Canada have insisted the government of India was involved, police have always said they had no evidence of that. 

But in a somber address to the House of Commons Monday afternoon, Trudeau said there is credibility to the allegations.

"Over the past number of weeks, Canadian security agencies have been actively pursuing credible allegations of a potential link between agents of the government of India and the killing of a Canadian citizen, Hardeep Singh Nijjar," he said.

"Any involvement of a foreign government in the killing of a Canadian citizen on Canadian soil is an unacceptable violation of our sovereignty. It is contrary to the fundamental rules by which free, open and democratic societies."

He said he raised the issue with Indian Prime Minister Narendra Modi in New Delhi last week and is demanding action.

"As you would expect, we've been working closely and co-ordinating with our allies on this very serious matter in the strongest possible terms. I continue to urge the Government of India to co-operate with Canada to get to the bottom of this matter."

Relations between Canada and India have been tense for months. In the last few weeks, Canada put trade talks with India on hiatus and cancelled a trade mission to the country that was planned for this fall.

Trudeau had a 16-minute discussion with Modi at the conclusion of the G20 on Sept. 10 but arranging the meeting was more difficult than expected. India refused to confirm it would happen until almost the last minute.

NDP Leader Jagmeet Singh, who is himself Sikh, delivered an emotional statement in the House of Commons following Trudeau's remarks.

"What we've just learned today in the House is something that shocks the safety and security that so many Canadians rely on," he said.

"It is outrageous. It is shocking and it is going to have deep and devastating impacts."

Singh, who also spoke briefly in Punjabi, said he grew up hearing stories that challenging India's record on human rights might prevent you from getting a visa to travel there.

"But to hear the prime minister of Canada corroborate a potential link between a murder of a Canadian citizen on Canadian soil by a foreign government is something I could never have imagined," Singh said.

He said people have come to Canada to be safe and free from violence and persecution.

"That safety and security that so many Canadians feel has now been rocked and has been shocked and has been destabilized."

Conservative Leader Pierre Poilievre said India needs to "act with utmost transparency" in the investigation.

"Because the truth must come out. We must know who performed the assassination, and who was behind the assassination," he said.

The news comes the day a Quebec judge officially begins her role leading a public inquiry into foreign interference in Canada. Last spring, national security adviser Jody Thomas said India was one of the top sources of foreign interference in Canada.

Thomas's comments came about two weeks before Nijjar was shot and killed.

This report by The Canadian Press was first published Sept. 18, 2023.