A union leader has filed a complaint with the Quebec Police Ethics Commissioner regarding the conduct of police officers disguised as protesters at last summer's North American leaders summit in Montebello, Que.

Dave Coles, head of the Communications Energy and Paperworkers Union of Canada, took part in the demonstration in August where three Sûreté du Québec officers dressed in black clothing and with bandanas over their faces were filmed carrying a rock and pushing through a line of riot police despite protesters' attempts to stop them.

At a news conference Tuesday, Coles said he hopes the complaint he filed Friday will achieve two goals.

"One is that we get to the bottom of who sent them in and why. Why were police sent in to disrupt a legitimate protest? I think Canadians need to know that. It's an affront against democracy," he said.

His other goal, he said, is to convince the prime minister to call a public inquiry into the matter.

Coles's complaint lists several sections of the Code of Ethics used by Quebec police that he alleges were violated by the undercover officers.

"I believe the three police officers were there to encourage and provoke clashes between the riot police and the protesters, so that the former would have an excuse to physically confront, intimidate and arrest the protesters and disperse the demonstration," the complaint said.

Riot police failed to protect protesters

The document also complains about the officers' superiors, who planned, directed and oversaw policing at the protest, and alleges that riot police at the site failed to properly protect protesters from the undercover officers.

The protest took place Aug. 20 and 21, 2007, when Prime Minister Stephen Harper, U.S. President George W. Bush and Mexican President Felipe Calderon met in Montebello to discuss the 2005 Security and Prosperity Partnership pact. The agreement was to boost co-operation on security, trade and public-health issues, but opponents of the pact fear it will erode Canadian sovereignty in areas such as natural resources, security and military issues.

During the protest, a video was posted on YouTube showing a confrontation between protest leaders, including Coles, and masked men the protesters alleged were undercover officers.

Later that week, Coles held a news conference showing that the masked men had the same boots as the officers of the Sûreté du Québec.

A day later, the provincial police admitted the men were their undercover officers but said they were only at the protest to locate and identify non-peaceful protesters in order to prevent any incidents.