Canada has spied abroad on behalf of the US National Security Agency, according to a classified document cited by public broadcaster CBC Tuesday.
Ottawa even opened up espionage posts overseas at the request of the US agency, CBC said, citing an NSA briefing paper leaked by fugitive former US government contractor Edward Snowden.
Through its own electronic spy agency, Communications Security Establishment Canada (CSEC), Ottawa worked with the NSA in "approximately 20 high-priority countries," some of which are trade partners, the document said, according to CBC.
Dated April 3, the "top secret" four-page document also contains sensitive operational details that CBC said it chose not to publish.
"CSEC shares with the NSA their unique geographic access to areas unavailable to the US," CBC quoted the briefing paper as saying.
It also described a "close co-operative relationship" between the two agencies, which exchange personnel, and claimed it is something "both sides would like to see expanded and strengthened."
The CSEC was sophisticated in its dealings, with "resources for advanced collection, processing and analysis" and "has opened covert sites at the request of NSA," the document reportedly states.
Thomas Drake, a former high-ranking NSA official turned whistleblower, said it was not surprising that Canada would agree to collaborate with Washington.
"That's been the case for years," he told CBC.
Late last month, CBC reported that Canada allowed America's National Security Agency to spy on G20 talks in Toronto in 2010 and at the G8 summit days earlier.
Wanted by US authorities for leaking thousands of classified documents, Snowden was granted temporary asylum in Russia.
Over the past six months, his leaks to select newspapers have revealed a massive scale of spying by Washington and other countries.