Amnesty International on Wednesday accused Canadian authorities of heavy-handedness and rights violations including "unjust arrests and detentions" at the G7 summit in La Malbaie, Quebec in June.
The protests were relatively small, with a few hundred demonstrators outnumbered at least two to one by riot police, and kept far from the conference site by huge fencing and patrols.
In fact the G7 leaders were more likely to spot a bear roaming the Canadian outback than flag-burning protestors who were once a staple of their gatherings.
Still, Amnesty said 40 of its members sent to monitor police actions around the G7 summit observed "several violations of freedom of expression, including the right to protest, unjust arrests and detentions."
"The police sought to deter, intimidate and interfere in the exercise of freedom of expression and the right to protest," said Genevieve Paul, co-author of the report.
Canadian Prime Minister Justin Trudeau hosted the leaders of Britain, France, Germany, Italy, Japan and the United States for the two-day summit at a luxury resort on the banks of the Saint Lawrence River.
Nearly 9,000 police from across Canada, with dog units and helicopter support, were mobilized to protect the leaders.
An estimated 70 percent of the G7 summit budget of about Can$600 million (US$465 million) was spent on security, according to Canadian officials.