TORONTO — A secret document leaked by former National Security Agency analyst Edward Snowden shows Canada's electronic spy agency used information gleaned from a free internet service at a Canadian airport to track the wireless devices of thousands of airline passengers.

The report indicates the Communications Security Establishment Canada was given information taken from wireless devices using the airport's Wi-Fi system over a two-week period. It's not clear which airport was involved.

The document shows the spy agency was then able to track travelers for a week or more as they showed up in other Wi-Fi locations in cities across Canada.

The Canadian Broadcast Corporation obtained the document and posted it to its website Friday.

The report, dated May 2012, is a 27-page PowerPoint presentation describing the spy agency's airport tracking operation.

According to the document, the agency tracked metadata including the location and telephone numbers of calls made and received but not the content.

The spy agency is supposed to collect primarily foreign intelligence by intercepting overseas phone and internet traffic. It is prohibited by law from targeting Canadians without a judicial warrant.

The agency's spokeswoman Lauri Sullivan said no Canadian or foreign travelers were tracked or targeted and no information was collected or used.

"The classified document in question is a technical presentation between specialists exploring mathematical models built on everyday scenarios to identify and locate foreign terrorist threats. The unauthorized disclosure of tradecraft puts our techniques at risk of being less effective when addressing threats to Canada and Canadians," Sullivan said.

The document indicates the passenger tracking operation was a trial run of a new software program the spy agency was developing with help from its U.S. counterpart, the National Security Agency.

The spy agency called the new technologies "game-changing," and said they could be used for tracking "any target that makes occasional forays into other cities/regions."

Sullivan said that in 2011, the agency's commissioner completed a review specifically focused on its metadata activities, finding them to be lawful. The commissioner is conducting another review of its metadata activities, she said.

Ontario Privacy Commissioner Ann Cavoukian told the CBC that it's "unbelievable" the Canadian spy agency would engage in that kind of surveillance of Canadians, saying it "resembles the activities of a totalitarian state."

Cavoukian earlier this week commended the efforts of Snowden to preserve civil liberties and encouraged Canadians to follow suit by insisting upon greater transparency and accountability from the federal government and the Communications Security Establishment Canada.