OTTAWA (AFP) - Canada allowed America's National Security Agency to spy on G20 talks in Toronto in 2010 and at the G8 summit days earlier, according to documents cited by public broadcaster CBC.

The NSA briefing notes provided by Edward Snowden, the former NSA contractor who is now a fugitive in Russia, reportedly detail a six-day spying operation run out of the US embassy in Ottawa.

The documents say the monitoring - conducted while President Barack Obama and 25 other foreign heads of government met on Canadian soil in June 2010 - was meant to "support US policy goals." They do not specifically describe the goals, but the G20 summit in Toronto focused on how to rouse a global economic recovery and prevent another financial crisis.

One proposal included a global tax on banks, an idea strongly opposed by both Washington and Ottawa, and which was eventually scratched.

G8 leaders met in Huntsville, 220km north of Toronto, before the G20 meeting took place.

The documents cited by CBC say the spying operation was "closely coordinated with the Canadian partner", the Communications Security Establishment Canada.

By law, the CSEC cannot target anyone in Canada without a warrant, and is prohibited by international agreement from getting the NSA to spy on its behalf.

Documents previously released by Mr Snowden exposed spying on world leaders.

The Guardian newspaper has said that Britain snooped on delegates of the Group of 20 during two gatherings in London in 2009, hoping to get an unfair advantage in negotiations or policy debates.