TORONTO - Calls for an independent review of police action during the weekend's G20 summit grew louder Wednesday as Ontario Premier Dalton McGuinty came under attack for special powers he granted police.

Provincial Conservatives accused the McGuinty government of failing to come clean about passing a law giving police the power to detain people in the summit security zone.

"This is his secret law, and the fact he kept it secret and has not had the courage to come out and talk about the reasons behind it are quite frankly slippery and cowardly," Conservative Leader Tim Hudak said.

"Most people would understand that extraordinary measures are needed in extraordinary times, but be honest about it; have the courage of your convictions as premier."

McGuinty has refused to say why cabinet passed the law in secret and never made it public.

His staff said Wednesday he won't be available to comment before the middle of next week.

Controversy over the law arose after the Liberal cabinet secretly agreed to a request from Toronto Police Chief Bill Blair for more powers.

Almost immediately after Blair said last Friday that officers had the right to stop and search people outside the G20 fences, reports surfaced of police searching and detaining people even far from the security zone.

Blair later admitted he didn't tell the public despite learning on the Friday that the new measures applied only inside the G20 fences, not outside.

Civil libertarians were incensed.

They also were angry that neither the province nor Blair clarified the provisions until after the G20 was over and the regulation, which was only enacted for a one-week period, had expired.

Amnesty International, the Public Service Alliance of Canada and the Civil Liberties Association have all called for an independent review of police behaviour.

"We are seriously concerned about the erosion of civil liberties in Toronto this (past) weekend," said PSAC president John Gordon.

Federal New Democrats also formally requested the House of Commons Public Safety committee be recalled to study security issues at both the G8 and G20 summits.

"Serious questions have been raised about the conduct of security personnel, violations of civil liberties, violence and property destruction, and the questionable political decisions that led to these problems," said New Democrat public safety critic Don Davies.

The Canadian Civil Liberties Association demanded an apology of the Ontario government for using "war-time legislation" to suspend people's rights.

The Public Works Protection Act dates to 1939 and was never updated until the G20 amendment.

Provincial New Democrats also demanded McGuinty accept responsibility for what they called a fiasco that infringed on people's civil liberties.

"There has been a complete lack of transparency, and now after the fact, a complete lack of accountability in terms of what went on," said NDP Leader Andrea Horwath.

"The premier needs to stand up and take responsibility for this. He needs to shoulder the blame, and he needs to tell the people what happened and why."