A new report about Toronto's billion-dollar G20 summit says police committed "widespread and systematic violations of constitutional rights," and demands that the Ontario and federal governments conduct a broader public inquiry into the matter.

The Canadian Civil Liberties Association (CCLA) and National Union of Public and General Employees are set to release the report Monday at 11 a.m.

While police actions around the June 26-27 summit have already spurred several investigations, Nathalie Des Rosiers, general counsel for the CCLA, said that none have been given a broad enough mandate to probe the role that CSIS and the RCMP played.

"The impact of the policing at the G20 was profoundly felt on many people," she told CTV.ca. "In our view, there are too many questions that are unanswered and that require answers before people will regain their public trust in the police."

Aside from calling for a comprehensive public inquiry, the report offers seven other recommendations, such as:

• reforming police policy and training to emphasize how the Charter of Rights and Freedoms applies to peaceful protests
• investigating the role that "undercover police informants" played among G20 protest groups
• creating legislation to govern "public order policing" that includes civilian oversight
• removing from police background check databases all charges related to the G20 that have not led to a conviction

The number of reported "illegal detentions and searches and excessive uses of force, cannot have simply been the actions of a few bad apples," the report states, adding that "it is difficult to view this situation as anything other than a failure of policy and training."

Policing around the international summit was as the largest ever in Canada during peacetime. When a small group of protesters vandalized property using "black block" tactics late in the afternoon of June 26, it led to a security crackdown.

Officers fanned out across the city searching for the culprits and "disregarded the constitutional rights of thousands" in the process, the report says.

"Peaceful protests were violently dispersed."

More than 1,100 people were arrested -- the largest mass arrests in Canadian history. Many have spoken out about how they were treated, including lawyers and academics. A number of lawsuits are also pending.

The report, "Breach of the Peace," is based on public consultations held in November with 63 people in Toronto and Montreal, as well as information from legal observers who the CCLA deployed on Toronto's streets during the G20 summit weekend.

Toronto Police and the Ontario Provincial Police were invited to attend the hearings but declined to take part.

"Much of the testimony we heard was shocking and appalling," union president James Clancy writes in the 59-page report.

"Over and over again, witnesses recounted their experiences involving the excessive violent dispersal of peaceful demonstrators by police and the dehumanizing treatment of many of those who were detained."

One of the many photographs in the report features John Pruyn, a 58-year-old Revenue Canada worker who had his artificial leg pulled off by police, who arrested him while he was sitting on the grass outside the provincial legislature.

While most of those charged in relation to the anti-G20 protests have been released without being convicted, a number of cases are still being heard by the courts.

One police officer is also facing criminal charges related to the protests.

The report, titled "Breach of the Peace," will be officially released at a press conference in Ottawa on Monday morning, which NDP public safety critic Don Davies and Liberal public safety critic Mark Holland are expected to attend.

With files from The Canadian Press