TORONTO - Ontario's outspoken ombudsman is clearing off his desk to find out why the province passed an "extraordinary" law in secret that sparked widespread confusion about police powers during the G20 summit.

The 90-day probe -- now his office's "top priority" -- will examine why the Ministry of Community Safety and Correctional Services resorted to the regulation, which many believed allowed police to arrest people who came within five metres of the summit security fence if they didn't produce identification.

It actually decreed that all streets and sidewalks inside the summit security fence were a "public work" just like courthouses -- meaning police could search people trying to enter the area. But neither the police nor politicians set the record straight until after the June 26-27 summit was over.

Ombudsman Andre Marin said even he was fooled.

"I thought the five-metre distance rule to the fence was a rather unusual new measure adopted by the government until I learned, just as the rest of us, that there was no such rule that was in effect," he said in an interview.

"So certainly, it got my attention. My antennas were raised when I saw that, and then the complaints started coming in."

Marin's office has received 60 complaints related to the G20, including one signed by a group of 129 academics from Toronto's York University.

"It's something that you can't ignore," Marin said.

Several of the complaints allege a "lack of transparency and public communication" about the law which led to an "atmosphere of secrecy and confusion and contributed to the violation of civil liberties," his office said in a release.

In response, Marin will examine whether it was necessary for the Ontario Liberals to adopt such an "extraordinary" regulation and how the government pushed it forward and communicated it to the public. He'll also look into how the police interpreted the regulation and reacted to those who were demonstrating.

"There are many, many questions in the public's mind as to the necessity of this regulation," Marin said.

"Did it have a chilling effect on the constitutional right freedom of speech? Did it have a chilling effect on demonstrators that day, who wanted their voices heard?"

Both McGuinty and Community Safety and Corrections Minister Rick Bartolucci have been "very genuine and forthcoming" in admitting that they weren't thorough in clarifying the law to the public, Marin said.

Last week, the premier admitted to The Canadian Press that his government could have done a better job to dispel confusion about the law during the explosive G20 protests, but rebuffed calls for an apology.

Bartolucci has insisted that the government did clarify the law, but acknowledged that there was a "lack of clarity" and they should have been "more aggressive" in getting the message out.

He also revealed Wednesday that the commissioner of community safety informed Toronto police Chief Bill Blair on June 25 -- when news broke of the secret law -- that there was some "ambiguity" about the new regulation. Blair assured the commissioner that he would "rectify" the situation, Bartolucci said.

Asked June 29 if there actually was a five-metre rule, Blair smiled and said, "No, but I was trying to keep the criminals out."

Marin has also been asked to probe the use of force by police during the summit, which saw about 1,000 people arrested after a group of black-clad protesters rampaged through Toronto's core, smashing windows and setting police cruisers alight.

But that's up to McGuinty, who has so far dismissed calls for a public inquiry, Marin said. The ombudsman also doesn't have the power to look into cabinet's deliberations on the regulation before it was passed.

He does have certain investigative tools which could force an inquiry, he said.

"We have the ability to subpoena witnesses, we have the ability to turn an investigation into an inquiry," Marin said.

"While we don't usually use those tools because they're not necessary, but if it becomes necessary, we have the necessary resources to do our job."

Laura Blondeau, a spokeswoman for Bartolucci, said the minister welcomes Marin's investigation and will co-operate fully.

Toronto's police services board, the civilian oversight body for the police, will also conduct an independent review of police actions during the G20.

Civil rights groups have been calling for an apology from the government and an independent inquiry into the mass detention of people and widespread use of police force.

The mass arrest is believed to be the largest in Canada's history, surpassing even the October Crisis in 1970 when the federal government invoked the War Measures Act.

Opposition parties embraced Marin's investigation, saying it will shed light on McGuinty's decision to do an end-run around the legislature in pushing the law through.

"This is a government that's out of touch," said Progressive Conservative critic Lisa MacLeod. "It's becoming tired and very secretive and Ontarians have had enough."

Only a full public inquiry will answer all the questions surrounding the summit, said NDP critic Peter Kormos.

"Will it cost money? Yes," said NDP critic Peter Kormos. "But we've already invested a billion dollars plus, and we've seen this debacle, this horror show. It would be money well spent to ensure that nothing like that ever occurs again."