New Delhi has been long sensitive to Sikh protesters in Canada.
Indian prime minister Narendra Modi accused Sikh protesters of inciting violence and damaging diplomatic premises.
In June, India criticised Canada for allowing a float in a parade depicting the 1984 assassination of Indian prime minister Indira Gandhi by her bodyguards, perceived to be glorification of violence by Sikh separatists. Relations between India and Canada remain tense, and Ottawa this month paused talks on a proposed trade treaty with India, just three months after the two nations said they aimed to seal an initial agreement this year. Modi, who held bilateral meetings with many world leaders during the G20 summit, did not hold one with Trudeau.
Canada has the highest population of Sikhs outside their home state of Punjab in India, and the country has been the site of many protests that have irked India.