The Canadian Broadcasting Corp. reported the Communications Security Establishment of Canada, Ottawa's National Security Agency counterpart, let the NSA conduct a six-day spying operation, using the U.S. Embassy in Ottawa as a base, as world leaders and delegates arrived in Ontario for the Group of Eight and Group of 20 summits in June 2010.
President Barack Obama was among the world leaders at the sequential summits, which ran for a day and a half each from June 25 to June 27.
The NSA spying was "closely coordinated with the Canadian partner," the CBC News report said, citing documents provided by former NSA contractor Edward Snowden.
"We cannot comment on specific foreign intelligence activities or capabilities," Rob Nicholson told the House of Commons defense committee during a testy exchange with New Democratic Party opposition leader Thomas Mulcair.
"CSEC cannot ask our international partners to act in a way that circumvents Canadian laws," Nicholson said.
"We know it is not allowed to ask," Mulcair shot back, saying Nicholson didn't answer the question but simply stated what the law was.
"The question was, did they do it? That's the question," he said. "Did CSEC obtain the authorization of a judge before authorizing and helping the Americans to spy on us in Canada during the G20 summit?"
Nicholson repeated his previous response and told Mulcair that should satisfy him, The Globe and Mail reported.
"We know it's prohibited, we know they're not allowed to ask, we know they need the authorization of the judge, and the question is: Did they respect the law, yes or no? And they failed to answer like usual," Mulcair said to Nicholson and the committee
"What is it about obeying the law that this so-called law-and-order Conservative government doesn't seem to understand?" he said, referring to the government of Prime Minister Stephen Harper.
Nicholson told the committee CSEC operations were supervised by an independent commissioner.
"That independent commissioner has indicated for the last 16 years that CSEC has complied with all Canadian laws," Nicholson said.
The G8 summit in Toronto and the G20 summit 135 miles north of Toronto in Huntsville, Ontario, focused on economic cooperation during the global financial crisis and Great Recession.
The G8 includes the United States, Canada, Britain, France, Germany, Italy, Japan and Russia.
Members of the Group of 20 are Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, Britain, United States and European Union.