The killing of a Sikh separatist in Canada last year was part of a broader campaign of violence against Indian dissidents directed by a senior official in the Indian government and an operative in the country’s spy agency, according to Canadian officials who cited intercepted Indian communications and other newly acquired information.

Canadian authorities have also identified at least six Indian diplomats serving in Canada who were directly involved in gathering detailed intelligence on Sikh separatists who were then killed, attacked or threatened by India’s criminal proxies, Canadian officials said.