[4] In 2016, Nijjar was placed on Canada's No Fly List and had his personal bank accounts frozen following allegations of his involvement in "terror training camps".

[17][18] In October 2024, Canada expelled six Indian diplomats, including the High Commissioner Sanjay Kumar Verma, as persona non grata.

This occurred after Canada said they provided India with "irrefutable evidence" of links between Indian government agents and the murders of both Nijjar and of Sukhdool Singh, who was shot in Winnipeg on 20 September 2023; Canadian officials say that the six officials were "directly involved in gathering detailed intelligence on Sikh separatists who were then killed, attacked or threatened by India's criminal proxies".

[24] According to The Globe and Mail, Nijjar told his friends that he was apprehended by the police because of his association with the architects of the 1995 assassination of Punjab's chief minister, Beant Singh; a claim he withheld from Canadian immigration authorities.

[34] After his death, the World Sikh Organization of Canada said that Nijjar "often led peaceful protests against the violation of human rights actively taking place in India and in support of Khalistan.

"[35] Nijjar had a dispute with Ripudaman Singh Malik, a Canadian Sikh who had been acquitted over involvement in the 1985 bombing of Air India Flight 182.

[25] The first accused him of being a "mastermind/active member" of Khalistan Tiger Force and said that suspects arrested in connection with the 2007 Shingaar cinema hall bomb blast had implicated him.

[25] The Indian government and intelligence agencies alleged that Nijjar visited Pakistan in 2012–14, where he met with militant leader Jagtar Singh Tara of Babbar Khalsa International, was recruited and groomed by Pakistan's intelligence agency, received arms and explosives training, and under Tara's directive, was sent to Canada in 2013 to receive handheld GPS device training.

[8] In 2015, the Indian government asked that Canadian authorities surveil Nijjar over suspicions of his involvement in a plot to transport ammunition into India using a paraglider.

"[28] In 2016, Surrey plumber Mandeep Singh Dhaliwal, was apprehended by the Indian police during a visit to Punjab, he later told the police that Nijjar had directed him to commit violent acts against "sect leaders," leading the Indian media to circulate articles claiming that Khalistani "terror training camps" were operating in the British Columbia wilderness.

[43][8] Following these allegations, the RCMP questioned Nijjar, and he was subsequently placed on Canada's No Fly List and had his personal bank accounts frozen.

[8] In a letter sent in 2016 to Canadian Prime Minister Justin Trudeau, Nijjar called the Indian government's accusations "fabricated, baseless, fictitious and politically motivated"[28] and part of a smear campaign seeking to discredit him.

"[45] The Hindustan Times reported that the Surrey unit of the Royal Canadian Mounted Police (RCMP) briefly detained Nijjar for questioning in April 2018, released him within 24 hours without laying any charges.

"[23] The same year, amid protests by Indian farmers against new agriculture laws, the Indian government filed a criminal case against him, one of a number of cases that authorities filed against Sikh activists living both at home and abroad; the government initially attempted to discredit the farmers' protest by associating it with Sikh nationalism.

[6] In 2022, India's National Investigation Agency (NIA) accused him of plotting to kill a Hindu priest in Punjab, and offered a reward of ₹1,000,000 (approximately CA$16,200) for any information that could help apprehend him.

"[8] The report summarizes accusations by the Indian government apparatus that Nijjar spearheaded various criminal activities in India, including the Ludhiana cinema bombing, and says that they did not provide compelling evidence to substantiate these claims.

"[8] The report confirmed Nijjar's close friendship with a member of the Khalistan Commando Force (KCF) via the member's brother,[8][47] and says Nijjar maintained a close relationship to Jagtar Singh Tara, a conspirator in the assassination of Beant Singh, and head of various Sikh militant groups, including the KCF and the Khalistan Tiger Force (KTF).

[49] On 18 June 2023, Nijjar was shot and killed in his pickup truck by two masked gunmen in the parking lot of the Guru Nanak Sikh Gurdwara in Surrey, British Columbia.

[51] Police received a report of a shooting at the gurdwara at 8:27 p.m.[31] The gunmen (whom investigators described as "heavier set") fled the scene by foot into a waiting car (later identified as a silver 2008 Toyota Camry) that sped away.

[10][52] Video footage and witness accounts compiled by The Washington Post showed a coordinated attack, involving at least six men and two vehicles.

[22] In September 2023, Prime Minister Justin Trudeau said Canadian security agencies have opened an investigation into Nijjar's killing, which officers suspect of having been ordered by India.

[64] In October 2024, Canadian officials said they had evidence of Indian government involvement in home invasions, drive-by shootings, arson and two homicides, those of Nijjar and of Sukhdool Singh, shot in Winnipeg on 20 September 2023.

Investigations had revealed that Indian diplomats intimidated and coerced Canadians,[65] who were seeking immigration documents and/or had family ties in India, to gather intelligence for the Research and Analysis Wing to pick targets who were then attacked by a gang led by Lawrence Bishnoi.

[58] On 21 September, India's foreign ministry spokesperson Arindam Bagchi branded Canada as a "safe haven for terrorists, for extremists, and for organized crime.

"[71] Politicians from both the ruling Bharatiya Janata Party and the opposition, as well as news anchors, commentators and former ambassadors, accused Trudeau of making the allegations for political gain.

"[74] India temporarily suspended the processing of visa applications for Canadian citizens on 21 September 2023 due to the "rift" between the countries; the Indian government blamed "security threats being faced by our High Commission and consulates in Canada" as the reason for the suspension.

[83][84] In October 2024, Canada expelled six Indian diplomats, including the High Commissioner Sanjay Kumar Verma, after Canada said the RCMP provided them with "irrefutable evidence" of links between Indian government agents and "homicides, extortion and violent acts"; India responded by calling the claims "preposterous" and expelling six Canadian diplomats in a tit-for-tat move.

[96] In November 2023, U.S. authorities claimed to have thwarted a plot by the Indian government to assassinate the U.S.-based Sikh separatist Gurpatwant Singh Pannun.

During a meeting with Canadian High Commissioner to India Cameron MacKay, Peters clarified that New Zealand's position on Hardeep Singh remained unchanged and that he was not questioning Canada's claim.

[99] Pakistan's foreign office said that India's "network of extra-territorial killings" has gone global, which is "a clear violation of international law and the UN principle of state sovereignty.