Canadian intelligence services say a man arrested trying to leave the country last week is a Russian spy with forged identity papers.
The man, who used the false name Paul William Hampel, will appear in court in Montreal on Wednesday with authorities calling for his deportation.
The intelligence agency said the man had spied on Canada for 10 years and worked for a successor to the KGB.
Court papers said he had obtained three Canadian passports by fraudulent means.
The man was arrested at Pierre Elliot Trudeau Airport on 14 November carrying a fake birth certificate, the documents said.
The Canadian authorities say that when they arrested the man he was carrying more than $5,000 in various currencies and three mobile phones.
The papers read: "Hampel's establishment of a legend based on Canadian documentation has provided him with the ability to covertly further the interests of the SVR [Russia's Foreign Intelligence Service] for over a decade both within Canada and abroad."
The SVR is one of the successors to the Soviet KGB, which was dissolved in 1991, dealing with foreign operations and intelligence-gathering.
The SVR was involved in "high-level espionage and frequently boasts of its theft of Western financial and industrial secrets to aid the failing Russian economy", the papers said.
The Russian embassy in Ottawa has not yet commented on the case.
A court hearing has been scheduled for Wednesday, but the man's lawyer has said he will ask for a postponement as he only met his client for the first time last week and wants more time to examine the evidence.
The spying charges are the first since 1996, when Canada expelled Dmitriy Olshevsky and Yelena Olshevskaya, who had taken the names of Ian and Laurie Lambert to work as sleeper SVR agents.