A photograph of late temple president Hardeep Singh Nijjar is seen on a banner outside the Guru Nanak Sikh Gurdwara Sahib in Surrey, British Columbia, Canada, Sept 18, 2023, where the Canadian Sikh leader was gunned down in his vehicle while leaving the temple parking lot in June. (THE CANADIAN PRESS VIA AP)

NEW DELHI/OTTAWA —India said on Tuesday it had expelled a Canadian diplomat with five days' notice to leave the country, just hours after Ottawa expelled a top diplomat of the South Asian nation and accused it of a role in the murder of a Sikh separatist leader.

The development was the latest in an escalating row between the two nations, with Canada saying on Monday it was "actively pursuing credible allegations" linking Indian government agents to the murder in June.

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The Canadian high commissioner, or ambassador, in New Delhi had been summoned and told of the expulsion decision, India's foreign ministry said in a statement. 

If proven true, this would be a great violation of our sovereignty and of the most basic rule of how countries deal with each other.

Melanie Joly, Foreign Minister, Canada 

"The decision reflects the government of India’s growing concern at the interference of Canadian diplomats in our internal matters and their involvement in anti-India activities," the ministry added.

Speaking about the Canadian government's move, Foreign Minister Melanie Joly said on Monday that Canada has expelled the Indian diplomat for his alleged involvement in the assassination of Canadian Sikh leader Hardeep Singh Nijjar in British Columbia.

The allegations against the Indian diplomat, she said, are very serious and, if these allegations were proven it would be a great violation of Canada's sovereignty.

"If proven true, this would be a great violation of our sovereignty and of the most basic rule of how countries deal with each other," Joly told journalists. "As a consequence, we have expelled a top Indian diplomat." 

Joly said she "expects India to fully collaborate with us and ultimately to get to the bottom of this."

On Tuesday, India dismissed the Canadian accusation as "absurd and motivated" and urged it instead to take legal action against anti-Indian elements operating from its soil.

The foreign minister also said she plans to take up the matter during an evening meeting with G7 foreign ministers in New York on Monday.

Canadian Prime Minister Justin Trudeau has meanwhile said that national security agencies are presently investigating "credible allegations" that the "agents of the government of India" could be involved in the killing of the prominent Canadian Sikh leader.

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"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," Trudeau said while addressing the Canadian House of Commons on Monday.

Nijjar had been a prominent advocate of the Khalistan movement, which seeks to establish an independent homeland for the Sikh community in India's northwestern Punjab region. Nijjar was killed outside the Guru Nanak Sikh Gurdwara temple in Surrey, British Columbia, on June 18.

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The Indian Embassy in Ottawa has not immediately reacted to the Canadian government's move.