India has told Canada that it must repatriate 41 diplomats by October 10, the Financial Times reported on Tuesday.

Ties between New Delhi and Ottawa have become seriously strained over Canadian suspicion that Indian government agents had a role in the June murder in Canada of a Sikh separatist leader and Canadian citizen, Hardeep Singh Nijjar, who India had labelled a “terrorist”.

Nijjar, 45, was the president of Guru Nanak Sikh Gurdwara temple in Surrey, British Columbia and advocated for the creation of a Sikh state known as Khalistan.

India has dismissed the allegation as absurd.

On September 21, Trudeau called on India to cooperate with an investigation into the murder of the separatist leader in British Columbia and said Canada would not release its evidence for their claims.

India suspended new visas for Canadians and asked Ottawa to reduce its diplomatic presence in the country on the same day.

Last week, the Indian foreign minister spoke to US Secretary of State Antony Blinken and US National Security Adviser Jake Sullivan about Canadian allegations of New Delhi’s possible involvement killing of the separatist leader in Canada.

Jaishankar said that New Delhi had told Canada it was open to looking into any “specific” or “relevant” information it provides on the killing.

Trudeau, who is yet to publicly share any evidence, said he has shared the “credible allegations” with India “many weeks ago”.

The Financial Times, citing people familiar with the Indian demand, said India had threatened to revoke the diplomatic immunity of those diplomats told to leave who remained after October 10.

Canada has 62 diplomats in India and India had said that the total should be reduced by 41, the newspaper said.

The Indian and Canadian foreign ministries did not immediately respond to requests for comment.

Talking to reporters, Canadian Foreign Minister Melanie Joly said: “We are in contact with the government of India. We take Canadian diplomats’ safety very seriously and we will continue to engage privately because we think diplomatic conversations are best when they remain private.”

Indian Foreign Minister Subrahmanyam Jaishankar had last week said there was a “climate of violence” and an “atmosphere of intimidation” against Indian diplomats in Canada, where the presence of Sikh separatist groups has frustrated New Delhi.