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

Ties between India and Canada have deteriorated in recent weeks after Prime Minister Justin Trudeau announced there were "credible allegations" of Indian involvement in the assassination of Sikh independence activist Hardeep Singh Nijjar.

Nijjar, 45, had been wanted by India for years and was gunned down outside a Sikh temple in Surrey, B.C., on June 18.

India has dismissed the allegation as absurd.

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 Oct. 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.

The High Commission of Canada in New Delhi told CBC News on Tuesday it had no comment. 

Indian Foreign Minister Subrahmanyam Jaishankar said earlier 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.

Days after Trudeau's bombshell announcement, India warned its citizens to exercise caution when travelling to Canada, citing concerns about "politically-condoned" hate crimes and violence.

Soon after, it stopped processing visitor visas in Canada.

At the same time, the High Commission of Canada said it was temporarily adjusting its staff presence at its commission and consulate locations in India, due to "some diplomats having received threats on various social media platforms."