VANCOUVER, British Columbia (AP) — Canadian police said they arrested three suspects Friday in the slaying of a Sikh separatist leader last June that become the center of a diplomatic spat with India, and are investigating possible ties between the detainees and the Indian government.

Three Indian nationals in their 20s identified as Kamalpreet Singh, Karan Brar and Karampreet Singh were arrested in Edmonton, Alberta on Friday morning in the slaying of 45-year-old Hardeep Singh Nijjar by masked gunmen outside Vancouver, police said.

Canadian Prime Minister Justin Trudeau sparked a diplomatic feud with India in September when he said that there were “credible allegations” of Indian involvement in the slaying of Nijjar.

India had accused Nijjar of links to terrorism, but angrily denied involvement in the slaying. In response to the allegatio ns, India told Canada last year to remove 41 of its 62 diplomats in the country. Tensions remain but have somewhat eased since.