Defence Minister Rob Nicholson says there is no evidence that Canada's electronic spy agency used airport Wi-Fi to track the electronic devices of air travellers.

His defence of the activities of the Communications Security Establishment Canada comes in the wake of a report that alleges CSEC captured information from smartphones and laptops using free airport Wi-Fi, without the travellers’ knowledge.

That report was based on a top secret document reportedly retrieved by U.S. whistleblower Edward Snowden.

According to the document, dated May 2012, the data were gathered at “a major Canadian airport,” though it wasn’t clear at which airport. The spy service then was able to track the electronic devices for several days after travellers left the airport and to track when the devices were used at other Wi-Fi hot spots in Canada and the U.S.

Nicholson was asked about the document several times during question period in the House of Commons Friday.

He responded that “nothing in the documents… showed that Canadian communications were targeted, collected, or used, nor that travellers' movements were tracked.”

Nicholson’s response was similar to a statement released by CSEC itself Thursday night, in which the agency insisted it had done nothing illegal.

The agency says it collected only metadata that identified travellers’ wireless devices. It did not gather information about the content of emails or calls sent or received from the devices, it said.

“CSE is legally authorized to collect and analyze metadata,” the agency said in a statement.

The agency says it is mandated by law to collect foreign signals “intelligence foreign signals” to protect Canada and Canadians, and that it directs its foreign intelligence activities only at foreign entities.

As for the classified document retrieved by Snowden, CSEC says the document was used in “a technical presentation between specialists exploring mathematical models built on everyday scenarios to identify and locate foreign terrorist threats.”

It then decried the release of the document as a threat to its security efforts.

“The unauthorized disclosure of tradecraft puts our techniques at risk of being less effective when addressing threats to Canada and Canadians,” it said.

The agency went on to say that its activities, including the collection and analysis of metadata, are authorized under the National Defence Act, and that the agency’s activities, policies and procedures are regularly reviewed by the CSE Commissioner to ensure they are lawful.

“The CSE Commissioner has never found CSE to have acted unlawfully. In fact, he has specifically noted CSE’s culture of lawful compliance and genuine concern for protecting the privacy of Canadians,” the agency said.

Last August, former CSEC commissioner Robert Decary issued a report in which he complained that it appeared that ordinary Canadians communications may have been illegally tracked, but that poor record-keeping meant he couldn't be sure.

Decary said his office was in the process of reviewing CSEC's practice of collecting metadata, to assess whether it was impacting Canadians' privacy.

CSEC said Thursday evening it looked forward to that review.

“The CSE Commissioner is currently conducting another review of CSE’s metadata activities. We welcome that review,” it said.

Last week, a British Columbia-based civil liberties group filed a lawsuit against the federal government, alleging much of CSEC’s intelligence-gathering activity violates the rights of Canadians.

Specifically, the association's lawsuit objects to the collection of electronic metadata, which it alleges violates the charter rights of Canadians.

In a statement of defence, the federal government said that the collection of metadata is critical to the fulfillment of CSEC's mandate and that such collections have prevented attacks against Canadians, both here and abroad.

"CSEC's ability to acquire metadata, as well as its ability to carry out activities ... that risk the incidental interception of private communications, has contributed to the prevention of attacks against Canadians, both in Canada and Canadian Armed Forces members abroad," the government’s statement of defence read.

The statement did not offer any specifics to back up the claim.