Prime Minister Justin Trudeau is accusing the government of India of involvement in the fatal shooting of a Canadian Sikh leader — a claim that will have seismic effects on an already shaky bilateral relationship.

Canadian citizen Hardeep Singh Nijjar was brazenly shot dead outside a Sikh temple in Surrey, B.C. on June 18.

Nijjar, a supporter of a Sikh homeland in the form of an independent Khalistani state, had been branded by the Indian government as a “terrorist” and accused of leading a militant separatist group — something his supporters have denied.

Now, Trudeau said, Canada’s national security apparatus has reason to believe that “agents of the Indian government” carried out the killing of this Canadian citizen, who also served as the president of Surrey’s Guru Nanak Sikh Gurdwara.

“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,” Trudeau said Monday in a speech to the House of Commons.

“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 conduct themselves.

“As you would expect, we have been working closely and co-ordinating with our allies on this very serious matter.”

A senior government source told CBC News that Trudeau has briefed the leaders of some of Canada’s closest allies about the case, including U.K. Prime Minister Rishi Sunak, French President Emmanuel Macron and U.S. President Joe Biden.

Trudeau also urged the Indian government to participate in the ongoing investigation and “co-operate with Canada to get to the bottom of this matter.”

He said some Indo-Canadians are feeling “angry” and “perhaps frightened right now.”

“Let us not allow this to change us,” he said.

Foreign Affairs Minister Mélanie Joly said she has ordered the expulsion of “a senior Indian diplomat.”

Joly’s office said that diplomat is Pavan Kumar Rai, the head of the Research and Analysis Wing (RAW), India’s foreign intelligence agency, in Canada.

WATCH: Canada expels Indian diplomat as it investigates death of Sikh leader

Canada expels Indian diplomat as it investigates death of Sikh leader

Foreign Affairs Minister Melanie Joly says allegations that an agent connected to the Indian government was behind the death of Canadian citizen Hardeep Singh Nijjar are ‘troubling’ and ‘completely unacceptable’ if true.

 

“My expectations are clear. I expect India to fully collaborate with us and get to the bottom of this,” Joly said.

Public Safety Minister Dominic LeBlanc said the RCMP is leading the murder investigation.

“We’ll hold the perpetrators accountable and bring them to justice,” he said.

The Mounties’ Integrated Homicide Investigation Team (IHIT) is responsible for the Nijjar file.

“It’s progressing,” RCMP Commissioner Mike Duheme told CBC News when asked about the investigation.

The World Sikh Organization of Canada, a group that represents Sikh interests, said Nijjar spoke of “threats to his life” before his alleged murder.

He also claimed he was being targeted by India’s intelligence agencies, the WSO said in a media statement.

Sikh group says ‘India actively targets Sikhs in Canada’

The WSO said “several other Canadian Sikhs are also understood to be under threat” and are on Indian “hit lists.”

“The significance of today’s announcement cannot be understated for Sikhs,” the WSO said.

“Today, the prime minister of Canada has publicly said what Sikhs in Canada have known for decades — India actively targets Sikhs in Canada.”

Trudeau said he raised the matter with India’s Prime Minister Narendra Modi last week at the G20 summit in New Delhi.

Trudeau and Modi have long had a frosty relationship.

After the bilateral meeting between the two leaders on the sidelines of that summit, the Indian government released a tersely worded communique that said Modi raised with Trudeau “strong concerns about continuing anti-Indian activists of extremist elements in Canada.”

The statement said there are elements in Canada “promoting secessionism” and “inciting violence against Indian diplomats, damaging diplomatic premises and threatening the Indian community in Canada.”

The Indian government called on the two countries to co-operate in dealing with “such threats.”

The Canadian communique on the same meeting made no mention of “secessionism.” It’s now clear why.

WATCH: Trudeau links India to killing of Canadian Sikh leader

Trudeau links India to killing of Canadian Sikh leader

Prime Minister Justin Trudeau on Monday accused the government of India of being involved in the fatal shooting of Canadian citizen Hardeep Singh Nijjar in Surrey, B.C., in June. CBC’s Evan Dyer breaks down what we know.

 

Last Tuesday, Trudeau and the Canadian delegation left India after an extended stay caused by a technical problem on the prime minister’s plane.

One member of the delegation was absent.

National Security Adviser Jody Thomas quietly left India for London, U.K. instead, a government source told CBC News.

She informed the U.K. government that Canada’s relations with India were about to get worse now that Canada had credible evidence linking India’s government to Nijjar’s death, the source said.

Trudeau also briefed the Opposition leaders personally Monday before rising to tell Canadians about this development.

WATCH: Opposition leaders react  

Opposition leaders react to Trudeau’s allegations about Sikh leader’s death

Conservative Party Leader Pierre Poilievre and NDP Leader Jagmeet Singh call on the Indian government to cooperate with Canadian authorities during their investigation.

 

Conservative Leader Pierre Poilievre said it’s “outrageous” that India may be behind Nijjar’s killing.

“Our citizens must be safe from extrajudicial killings. Canadians deserve to be protected on Canadian soil. We call on the Indian government to act with utmost transparency as authorities investigate this murder. The truth must come out,” Poilievre said.

“Let us lock arms and join hands in condemning this murder, standing with the family and the friends of this victim. Let’s put aside our difference to stand up for the rule of law. One law for all our people.”

In his own speech, NDP Leader Jagmeet Singh blasted the Indian government under Modi, a Hindu.

Singh said the Modi-led government has been “one of division, violence, persecution” with a known pattern of “attacking those who are critical” of its actions.

WATCH: Minister says government has been ‘confronting’ Indian officials 

LeBlanc: India’s possible link to killing of Sikh leader ‘an extraordinary violation of Canada’s sovereignty’

Minister of Public Safety Dominic LeBlanc says the government has been ‘confronting’ Indian officials since it became aware of ‘credible allegations’ a ‘number of weeks ago.’

 

Singh said he’d use “every tool” at his disposal to “bring those responsible to justice.”

“We will ensure that no rock is unturned, that every possible link is examined,” Singh said.

He said that the public inquiry into foreign interference, which was prompted by allegations of Chinese meddling, should also look at India and its actions in Canada.

B.C. Premier David Eby said he was “deeply disturbed and angered” by the news.

“In light of these revelations, we will do all we can to enhance protection for the people of British Columbia against the violence or threats of state actors,” he said in a media statement.

“Our government will fully and enthusiastically support any federal efforts to ensure those responsible are held personally accountable.”