VANCOUVER, British Columbia (AP) — A fourth Indian national living in Canada has been charged in the slaying of a Sikh separatist leader last June that became the center of a diplomatic spat with India.

British Columbia’s Integrated Homicide Investigation Team said in a release late Saturday that 22-year-old Amandeep Singh was already in the custody of Peel Regional Police in Ontario for unrelated firearms charges.

“IHIT pursued the evidence and gained sufficient information for the BC Prosecution Service to charge Amandeep Singh with first degree murder and conspiracy to commit murder,” the police statement said.

Police also confirmed that Singh is an Indian national splitting his time in Canada in Brampton, Ontario; Surrey, British Columbia; and Abbotsford, British Columbia.

Investigators say no further details of the arrest can be released due to ongoing investigations and court processes.

Earlier this month, police arrested three Indian nationals — Karan Brar, Kamalpreet Singh and Karanpreet Singh — in Edmonton and charged them with first-degree murder and conspiracy to commit murder in the death of Hardeep Singh Nijjar, who was gunned down in the parking lot of the Surrey, British Columbia, Sikh temple where he was president.

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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 allegations, India told Canada last year to remove 41 of its 62 diplomats in the country. Tensions remain but have somewhat eased since.

A spokesman for the Guru Nanak Sikh Gurdwara did not immediately respond to a request for comment.

Protesters from the temple rallied outside the provincial courthouse in Surrey last Tuesday when the three men charged in the case appeared via video link.

The arrests have heightened scrutiny on Canada’s permitting process for international students after revelations that a video posted online in 2019 by an India-based immigration consultancy showed Brar saying his “study visa has arrived” while a photo showed him holding up what appeared to be a study permit.

Immigration, Refugees and Citizenship Canada had said it cannot comment on active investigations or individual cases when asked about the suspects’ immigration status.