TORONTO - The Ontario government was opportunistic when it gave police wartime powers during the G20 summit in Toronto, resulting in a mass violation of civil rights in peacetime, ombudsman Andre Marin said Tuesday.

The Liberal government quietly promoted the use of a "likely illegal regulation" to give police "extravagant" powers on the eve of the June summit, Marin said. Police, he added, compounded matters with deliberate miscommunication about the reach of their new powers.

"Apart from insiders in the government of Ontario, only members of the Toronto Police Service knew that the rules of the game had changed, and they were the ones holding the 'go directly to jail' cards," he wrote in his report.

More than 1,000 people were arrested during the G20 weekend in Toronto after a small group of protesters clad in black burned police cars and smashed store windows.

"Many of those stopped and questioned by police under the Public Works Protection Act were involved in demonstrations, but many others were simply Torontonians going about the activities of their daily lives," Marin wrote in his report, "Caught in the Act."

The act was used "to intimidate and arrest people who had done no harm," he added.

Police and politicians allowed everyone to believe the law gave police the power to demand identification and detain anyone within five metres of the G20 security fences.

In reality, the update of a 1939 law designed to protect public buildings during war allowed police to ask for identification from people entering the security zone, not outside it.

Marin said he was "bewildered" when Toronto Police Chief Bill Blair referred to a five-metre rule, which did not exist. It should have been called a five-kilometre rule given police were stopping and searching people very far from the G20 security fences, he added.

Blair refused to co-operate with the ombudsman's investigation and also declined to have his officers answer Marin's questions.

The original 1939 regulation was passed after Canada declared war on Germany, to protect public buildings such as courthouses. Its use during the G20 "was of dubious legality and no utility," Marin wrote.

"It was opportunistic and inappropriate to use a war measure that allows extravagant police authority to arrest and search people in the name of public works," he wrote.

"Here in 2010 is the province of Ontario conferring wartime powers on police officers in peacetime."

The decision by the Liberal cabinet should not have been kept shrouded in secrecy, added Marin.

"Going into the weekend of the G20 summit, no one knew about the regulation -- not the public, not the press, city administrators or even key members of the Integrated Security Unit in charge of summit security," he said.

"Worse, the ministry's decision not to publicize the regulation entrapped citizens who took the trouble to inform themselves of their rights and wound up caught in the act's all but invisible web."

The ombudsman also blasted the Ministry of Public Safety for failing to ensure that police were adequately trained on the regulation, which he said contributed to the "chaos and confusion" on city streets during the summit.

"The ministry simply handed over to the Toronto Police inordinate powers, without an efforts made to ensure those powers would not be misunderstood," wrote Marin.

"It may have been the best kept secret in Ontario's legislative history. By changing the rules of the game without real notice, (it) acted as a trap for the responsible."

Marin launched a 90-day probe after getting 167 complaints about the so-called secret law governing police powers during the G20.