The red-faced Sûreté du Québec promised to review their practices after three of their officers were caught posing as protesters trying to confront a line of officers at this week's Montebello summit.
Both the provincial police and federal Public Safety Minister Stockwell Day defended the police infiltration of protests as legitimate work, however, and insisted that the officers were trying to prevent violence, not incite it.
At the same time, the union leader who confronted the undercover officers, Communications, Energy and Paperworkers Union of Canada president David Coles, said he intends to file charges against the provincial police officers. He and opposition politicians have demanded an inquiry, insisting the police tried to discredit protests by sparking violence.
Videotaped footage of the incident shows the three disguised Sûreté du Québec officers wearing masks and holdings rocks in their hands, walking near a phalanx of officers in riot gear, while Mr. Coles tries to shoo them away, demanding they put down their rocks.
The officers refuse, and one swears and shoves Mr. Coles, and the union leader begins to accuse them of being police officers.
Chanting youths from the so-called Black Bloc told Mr. Coles that the three had been trying to get them to act more aggressively against the police.
Yesterday, a senior Quebec Provincial Police officer, Inspector Marcel Savard, said the clip shows only a portion of the events.
Earlier, the undercover officers had infiltrated a separate group of "extremists" and one of them handed an officer a rock, he said. The officers left the group and ended up in a crowd of peaceful demonstrators.
"He had a choice, a very quick choice to make," Insp. Savard said. He held onto the rock because "he was still hoping that his cover was good ... [but]he never had the intention of using that rock."
He added that undercover work is a legitimate, and standard, form of police work. "If there are methods or procedures that need to be changed or adjusted, you can be reassured, that will be done," he said.
The force had initially denied that their officers were disguised as protesters, but admitted it after the footage circulated widely on YouTube.
Neither Insp. Savard nor Mr. Day would say yesterday whether the RCMP, which was in charge of security for the summit, gave the Quebec force permission to deploy undercover officers. Mr. Day said that information was "operational details that I don't get into."
After a news conference in Vancouver, Mr. Day said he would not deter police from using such tactics.
"You can't start getting politicians making the calls, saying, 'It's okay for you to use undercover agents in this drug operation over here, but you can't use them in that over there,' " he said.
He said he got assurances that the RCMP does not instigate violence.
Mr. Day also said that the three officers were identified because they were not throwing rocks like other protesters - although reporters at the scene said they did not see extensive rock-throwing until long after the incident with the undercover officers.
Critics did not buy Quebec Provincial Police's explanation and said Ottawa has to give the public a more detailed accounting.
"Does this mean the next time there is a demonstration against the war in Iraq or to preserve health care, we may be in a situation where there will be police officers holding rocks?" asked NDP MP Peter Julian. Mr. Coles said he believes the police acted on political orders to discredit protesters, and that an inquiry would find that politicians gave the police orders, just as they did at the 1997 APEC protests in Vancouver,
"They were sent in to agitate, to try to create trouble," Mr. Coles said. "I say the politicians are in this up to their eyeballs. They were at APEC and they are in this one."
Martin Courcy, an expert in conflict management who has advised several police forces in Quebec, including the SQ, says the mere fact an officer was holding a rock was an act of provocation.
"They could serve as models to others, and in that sense there's provocation," he said. Police infiltration is meant to defuse conflicts. "In this case, they didn't defuse conflict, they provoked conflict."