It's not everyday that the leader of a government flat-out accuses another government(or agents of same)of being behind the killing of a citizen in their country. But it happened yesterday in the Canadian House of Commons, when PM Justin Trudeau made that charge. 1/
This has to do with the murder of 45 year old Hardeep Singh Nijjar in Surrey, BC in June of this year, allegedly by 2 people who fled the scene. Nijjar was a fierce advocate for the creation of a Sikh separatist state in India; in turn, India labeled him a terrorist in 2020. 2/
A good place to get info on the whole case is CBC News; I'll provide the link below. Reuters reported that the U.S. assisted Canada in the intelligence in this case(although the rest of the Five Eyes intelligence alliance is reluctant to step into the case).
For info: